taxonID	type	description	language	source
963987EEFFC2FFB0FF56FA4D5852F81D.taxon	description	New records. ALGERIA: Algier: Algier,?, 1 ♀ (leg. A. Weis); Guelma: Guelma, 36 ° 28 ′ 44 ″ N / 7 ° 23 ′ 57 ″ E, 29.3.2016, 1 ♀ (leg. A. Laouar); Relizane: Ammi Moussa, 5.1.1904, 1 ♂ (leg.?); Skikda: Skikda, Ecole d’agriculture, 36 ° 53 ′ N / 6 ° 54 ′ E, 9.5.2002, 1 ♀ (leg. Maatallah); Tissemsilt: Teniet el Haad, 10.5.1895, 1 ♂ (leg.?); Tizi Ouzou: Bastos, 36 ° 41 ′ N / 4 ° 03 ′ E, 26.4.2010, 1 ♀ (leg. Y. Korichi). MOROCCO: Fès-Meknès: 12 km E Ifrane, 9.5. – 10.5.1997, 1 ♂ (leg. J. Halada); Marrakesh-Safi: SE Marrakesh, 10 km N Talatast, 16.5.1996, 1 ♀ (leg. H. Zettel); Tanger-TetouanAl Hoceima: Bab Bered, 34 ° 59 ′ N / 4 ° 50 ′ E, 1300 m, 12.5.2015, 1 ♀ (leg. K. Denes). TUNISIA: Béja: 10 km S Nefza, 18.4.2001, 4 ♀, 1 ♂ (leg. M. Halada); Jendouba: 20 km S Tabarka, 16.4.2001, 1 ♂ (leg. M. Halada).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC2FFB0FF56FA4D5852F81D.taxon	distribution	Distribution. Maghreb (Morocco, Algeria, Tunisia). Pollen hosts. Oligolectic on Ranunculus (Ranunculaceae) (Sedivy et al. 2008). Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC3FFB1FF56FF585852FC9C.taxon	description	New records. CYPRUS: Paphos: Paleokastro, 16.3.1981, 1 ♀, 1 ♂ (leg. H. Teunissen). IRAQ: Dahuk: E Mangesh, 1046 m, 37.02304 ° N / 43.15054 ° E, 1 ♂ (leg. D. Baiocchi). ISRAEL AND PALESTINE: Tel Aviv District: Ramat Aviv, 32.130 ° N / 34.802 ° E, 6.3.2015, 1 ♂ (leg. G. Pisanty). SYRIA: Rif Dimashq: Ghouta E Damascus, 1.5.1952, 1 ♂ (leg. E. Schmidt). TURKEY: Adıyaman: Nemrut Dağı, Eski Kahta, 1400 m, 16.5.1990, 1 ♀ (leg. C. Schmid-Egger); Bingöl: 20 km W Bingöl, 1450 m, 18.5.1977, 1 ♂ (leg. F. Ressl).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC3FFB1FF56FF585852FC9C.taxon	distribution	Distribution. Western to eastern Turkey, Cyprus, northern Iraq and Levant (Syria, Lebanon, Israel and Palestine). Pollen hosts. Probably oligolectic on Ranunculus (Ranunculaceae) (Sedivy et al. 2008, as Chelostoma species 2). Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC3FFB6FF56FC4F5AB0FCEE.taxon	description	New records. CYPRUS: Kyrenia: 5 km E Girne, 35.34 ° N 33.47 ° E, 10.4.2007, 1 ♂ (leg. C. Schmid-Egger); Larnaka: Lefkava, 14.4.1983, 4 ♂ (leg. M. Kraus); Lefke: Yerasa, 20.3.1948, 1 ♀ (leg. G. A. Mavromoustakis); Limassol: Troodos, Kato Platres S Foini, 900 m, 1.5.2011, 4 ♀ (leg. C. Sedivy, A. Müller); Nicosia: Kykkos, 34 ° 58 ′ N / 22 ° 44 ′ E, 800 m, 11.5.2014, 1 ♀ (leg. M. Kafka); Paphos: Paphos env., 26.3. – 2.4.1995, 1 ♂ (leg. J. Wimmer). GREECE: Aegean Islands: Kos, Kyparissodassos, 36.8536 ° N / 27.2316 ° E, 6.4.2012, 1 ♂ (leg. P. Toutziarakis); Chios, Armolia, 38.2735 ° N / 26.0444 ° E, 9.4.2013, 1 ♂ (leg. G. Nakas); Lesvos, Aspropotamos, 39.286 ° N / 26.3682 ° E, 5.5.2012, 1 ♀ (leg. A Chroni). IRAN: Fars: Yasuj, Sarb-e Taveh, 30.545 ° N / 51.61 ° E, 2030 m, 4.5.2016, 1 ♂ (leg. M. Kafka); Ilam: Sar Joob, 33.933 ° N / 47.368 ° E, 1930 m, 13.5.2016, 1 ♀ (leg. M. Kafka); Lorestan: Dorud, Lanjabad, 33.419 ° N / 48.986 ° E, 960 m, 10.5.2016, 1 ♀ (leg. M. Kafka). IRAQ: Dahuk: Mount Gara, 1912 m, 37.015833 ° N / 43.350556 ° E, 11.5.2023, 5 ♂ (leg. D. Baiocchi). ISRAEL AND PALESTINE: Central District: Judean Foothills, Ya’ar Adulam, 3.4.2013, 1 ♀ (leg. Y. Berner); Haifa District: Carmel NP, 0.9 km SE Bet Oren, 32 ° 43 ′ 21 ′ N / 35 ° 00 ′ 45 ›› E, 264 m, 25.3.2016, 1 ♂ (leg. A. Dorchin); Jerusalem District: Ya’ar Yish’i, 18.4.2016, 1 ♀ (leg. A. Dorchin); Northern District: Meron NR, 1.2 km SSW Meron field school, 32 ° 59 ′ 55 ″ N / 35 ° 23 ′ 31 ″ E, 998 m, 3.4.2016, 1 ♂ (leg. A. Dorchin); Southern District: Judean Foothills, Lakhish, 19.3.2013, 1 ♀ (leg. T. Shapira). JORDAN: Ajloun: 10 km N Ajloun, 310 m, 22.5.2007, 1 ♀ (leg. Z. Kejval); Amman: 20 km W Amman, 22.04.2007, 5 ♀ (leg. C. Praz, C. Sedivy, A. Müller); Irbid: S Irbid, 13.4.2009, 24 ♀, 3 ♂ (leg. M. Snizek); Jerash: 10 km N Jerash, 23.4.2007, 6 ♀ (leg. C. Praz, C. Sedivy, A. Müller). SYRIA: Al-Quneitra: Golan Heights, 17 km E Qiryat Shemona, 2 km SE Zomet, 33 ° 13 ′ N / 35 ° 45 ′ E, 16.5.1996, 1 ♀ (leg. M. Hauser); As-Suwaida: Ganawat, 16.5.1995, 1 ♀ (leg. K. Denes); Hama: Nahr al Bared, 50 km NW Hama, 30.4.2000, 1 ♂ (leg. F. Kantner); Rif Dimashq: Bloudan, 16.5.1995, 1 ♀ (leg. K. Denes). TURKEY: Adana: Pozantı-Tekir, 37 ° 31 ′ N / 34 ° 57 ′ E, 1300 m, 7.6.2008, 2 ♂ (leg. M. Kafka); Adıyaman: Kuyucak, 8.6.1998, 1 ♀ (leg. M. Snizek); Amasya: Amasya, 488 m, 22. – 24.5.1959, 2 ♂ (leg. K. Guichard, M. Harvey); Ankara: Çamlıdere, 37.6596 ° N / 30.72316 ° E, 26.5.2002, 1 ♀ (leg. W. - H. Liebig); Antalya: Korkuteli, 7 km SW Kargin, 36 ° 37 ′ 571 ″ N / 30 ° 59 ′ 704 ″ E, 23.05.2009, 2 ♀ (leg. H. Özbek); Burdur: Burdur, 900 m, 27.4.1960, 2 ♂ (leg. Epping); Gaziantep: Yamaçoba, 40 km W Gaziantep, 29.4. – 1.5.2001, 1 ♂ (leg. I. Trojan); Hatay: Bademli, 6 km W Hassa, 860 m, 13.5.2002, 1 ♀ (leg. H. Özbek); Izmir: Boz Dağı, 1.6.1990, 2 ♀ (leg. P. Witzgall); Konya: 30 km S Akşehir, 24.6.1998, 2 ♀ (leg. J. Halada); Mersin: Aslanlı, 30 km N Erdemli, 17.6.1998, 12 ♀ (leg. M. Halada); Muğla: Knidos, 18.4.1981, 1 ♀ (leg. K. Warncke); Osmaniye: Aslanli Beli, 970 m, 13.5.2002, 2 ♀, 1 ♂ (leg. H. Özbek); Siirt: 20 km NW Şirnak, 1500 m, 5.6.1980, 1 ♀ (leg. K. Warncke); Sirnak: S Beytüşşebap, 13.6.1984, 1 ♀ (leg. K. Warncke); Tokat: 5 km N Turhal, 500 m, 1.6.1988, 1 ♀ (leg. H. Wiering).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC3FFB6FF56FC4F5AB0FCEE.taxon	distribution	Distribution. Greece (mainland, Aegean Islands), Turkey, Cyprus, northern Iraq, Iran, Levant (Syria, Lebanon, Israel and Palestine, Jordan). Subspecific classification. The comparison of one pair of C. diodon from Cyprus with the types from Amasya in Turkey prompted Mavromoustakis (1951) to separate the Cypriot specimens as a subspecies of its own, i. e. C. diodon cypriacum. This separation was based on a weaker and sparser punctation and a denser and more whitish pilosity in the specimens from Cyprus. However, these differences could not be confirmed after examination of numerous specimens from all over the distribution range of C. diodon. Pollen hosts. Oligolectic on Asteroideae and Cichorioideae (Asteraceae) with a clear preference for the former subfamily (Sedivy et al. 2008). Flower records: Anthemis libanotica (Mavromoustakis 1951), Glebionis coronaria, Picris altissima (label records).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC3FFB6FF56FC4F5AB0FCEE.taxon	description	Nesting biology. Several females were observed to enter their nests in dried wood of old houses (Mavromoustakis 1951).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC4FFB7FF56FA215B06FC5E.taxon	description	New records. ALGERIA: Batna: Aurès, Menaa, 1200 m, 26.4.1986, 1 ♀, 1 ♂ (leg. Gentmeier); Biskra: Biskra, 4.1.1904, 3 ♀ (leg. Meyer); Chlef: Ech Cheliff,?, 1 ♂ (leg.?); Mila: Oulad Aziz, 36 ° 27 ′ N 6 ° 16 ′ E, 22.4. – 10.5.2013, 15 ♀ (leg. Abderrezak); Saïda: 8 km NO Ain Ouarka, 6.4.1983, 1 ♀ (leg. R. Leys, P. van der Hurk); Sidi Bel Abbès: 23 km NE Ras el Ma, 26.4.1983, 1 ♀ (leg. H. Teunissen). MOROCCO: Casablanca-Settat: Oueled Sghir, 32.8379 ° N / 7.6216 ° W, 507 m, 27.3. – 28.3.2018, 1 ♂ (leg. A. Sentil, I. El Abdouni); Fès-Meknès: 15 km SE Sefrou, 26.5.1995, 2 ♀ (leg. M. Halada); Marrakesh-Safi: 30 km SW Asni, 31 ° 03 ′ N / 8 ° 06 ′ W, 22.4.1996, 2 ♀ (leg. J. Gusenleitner); Oriental: Guercif, 2 km S Debdou, 1500 m, 33.9495 ° N / 3.0524 ° W, 11.5.2022, 1 ♀ (leg. T. Wood); Rabat-Salé- Kénitra: Haddada, 34.1283439 ° N / 6.5592276 ° W, 125 m, 11.3.2019, 1 ♂ (leg. L. Hamroud, P. Lhomme); Souss-Massa: Taourirt Ouazzal, 13 km ENE Tafraoute, 29 ° 46.497 ′ N / 8 ° 51.581 ′ W, 1390 m, 22.4.2019, 1 ♀ (leg. A. Müller); Tanger-Tétouan-Al Hoceima: Jebel Dehedouh, 5 km SW Ketama (Rif Mts.), 1750 m, 6.6.1992, 1 ♂ (leg. H. de Jong). PORTUGAL: Faro: Algarve, Sao Braz de Alportel, 19.4.1987, 1 ♀, 1 ♂ (leg. J. Teunissen). SPAIN: Alicante: Alcoy, Benifallim, 900 m, 5.2.2000, 1 ♀ (leg. E. Scheuchl); Almeria: Andalucia, Nijar, 36 ° 59 ′ 0 ′′ N / 2 ° 14 ′ 06 ′′ W, 23.5.2018, 1 ♀ (leg. J. Smit); Barcelona: Papiol, 27.3.2010, 1 ♂ (leg.?); Cataluna: Aldover, 6 km N Tortosa, 4.5.2000, 1 ♀ (leg. E. Scheuchl); Granada: Lanjaron, S Sierra de Nevada, 4.5.2003, 1 ♀ (leg. M. Halada); Huelva: El Rocio, Coto Doñana National Park, 37 ° 07 ′ 13 ′′ N / 6 ° 26 ′′ 38 ’’ W, 6.4.2003, 2 ♀, 2 ♂ (leg. S. Roberts); Huesca: Manzon, 22.4.1984, 1 ♀ (leg. H. Teunissen); Madrid: Rivas-Vaciamadrid, Canal de Manzanares to Camino de Uclés, 40.3217 ° N / 3.5633 ° W, 19.5.2021, 1 ♀ (leg. T. Wood); Málaga: Yunquera, 40 km W Malaga, 29.4.2003, 1 ♀, 1 ♂ (leg. J. Halada); Murcia: 7 km SSE Puerto Lumbreras, 4.4.2010, 1 ♀, 1 ♂ (leg. P. Bogusch, J. Habermannova, J. Straka); Saragossa: Belchite, 40 km SSE Saragossa, 41.18 ° N, 0.44 ° W, 4.4.1999, 1 ♀, 1 ♂ (leg. C. Schmid-Egger); Sevilla: Aznalcazar, 25 km SWW Sevilla, 37.302 ° N / 6.260 ° W, 8.4.2010, 1 ♀, 6 ♂ (leg. C. Schmid-Egger); Tarragona: Ulldemolins, 30.5.1985, 1 ♀ (leg. Schmidt). TUNISIA: Gabès: 50 km W Matmata, 33.33 ° N / 9.25 ° E, 21.3.2001, 1 ♀ (leg. C. Saure); Gafsa: Gafsa, 5.4.2001, 4 ♀ (leg. M. Halada); Jendouba: Ain Soitane, 9.5.2006, 1 ♂ (leg. P. Kresl); Kasserine: Sbeitla, 12.4.1998, 1 ♀ (leg. K. Denes); Kebili: Jemna, 33 ° 35 ′ 493 ′′ N / 9 ° 00 ′ 507 ′′ E, 30.3.2008, 1 ♀ (leg. P. Bogusch); Médenine: Djouama, 33.15 ° N / 10.16 ° E, 26.3.2001, 1 ♀ (leg. C. Schmid-Egger); Nabeul: Hammamet, 15.3.1996, 1 ♂ (leg. K. Denes); Sidi Bouzid: Sidi Bouzid, 12.4.1999, 2 ♀ (leg. K. Denes); Sousse: M › saken, 20.4. – 21.4.1998, 1 ♀ (leg. K. Denes); Tataouine: Ksar Hadada, 4.4.1998, 2 ♀, 2 ♂ (leg. K. Denes).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC4FFB7FF56FA215B06FC5E.taxon	distribution	Distribution. Iberian Peninsula (Portugal, Spain), Maghreb (Algeria, Morocco, Tunisia). Pollen hosts. Oligolectic on Brassicaceae (Sedivy et al. 2008). Nesting biology. Unknown. A female was observed to collect mud on the ground (I. Cross, personal communication).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC5FFB5FF56FBF15852FE3A.taxon	description	Chelostoma quadrifidum Kriechbaumer, 1879: 312. Type material: Holotype ♂, “ Bozen ” (Italy), type depository unknown. Synonymy with Heriades appendiculatus Morawitz in Dalla Torre (1896). Synonymy with Chelostoma emarginatum (Nylander) in Schwarz et al. (1996).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC5FFB5FF56FBF15852FE3A.taxon	description	Literature records. AUSTRIA: Burgenland, Niederösterreich, Oberösterreich, Steiermark (Schwarz et al. 1996). AZERBAIJAN: Ordubad (Proshchalykin & Maharramov 2020). CROATIA: Bjelovar-Bilogora, Istria, Primorje-Gorski (Józan 2009). CZECH REPUBLIQUE: Bohemia, Moravia (Straka et al. 2007). FRANCE: Charente, Corrèze, Gironde, Lot-et-Garonne, Rhône, Tarn (Benoist 1929). HUNGARY: everywhere (Józan 2011). GEORGIA: Kacheti: Lagodekhi (Kirkitadze & Japoshvili 2015). IRAN: Gilan (Nadimi et al. 2013). ITALY: Aosta Valley, Calabria, Campania, Emilia-Romagna, Lazio, Piemonte, Sicilia, Toscana, Trentino-Alto Adige, Umbria, Veneto (Pagliano 1994, 1995; Comba 2019). NORTH MACEDONIA: Southwest: Ohrid (Zanden 1984). PORTUGAL: Algarve, Baixo Alentejo, Coimbra, Guarda, Trás-os-Montes (Diniz 1989; Torres et al. 2012; Baldock et al. 2018). SLOVAKIA: Straka et al. (2007). SLOVENIA: Submediterranean and subpannonian region (Gogala 1999, 2014). SPAIN: Almeria, Barcelona, Córdoba, Girona, Jaén, Madrid, Valladolid, Zaragossa (Torres et al. 2012; Ortiz-Sánchez et al. 2023). SWITZERLAND: Ticino, formerly Vaud, Geneva (Praz et al. 2023). TURKEY: Adıyaman, Amasya, Ankara, Antalya, Aydın, Bilecik, Bingöl, Bursa, Çanakkale, Çorum, Erzincan, Hakkari, Istanbul, Konya, Mersin, Muğla, Osmaniye, Samsun, Şanlıurfa, Şırnak, Yozgat (Özbek 2011). New records. AUSTRIA: Wien: Wien, Jedlesee, 20.5.1951, 1 ♀ (leg. B. Pittioni). AZERBAIJAN: Lankaran: Lankaran, 16. – 17.1999, 1 ♀ (leg. Dolin, Andreewa); Ordubad: Mazra, 39.03 ° N / 45.55 ° E, 2.5.2018, 1 ♀ (leg. M. M. Maharramov). BOSNIA AND HERZEGOVINA: Posavina: near Zupania along road to Vicovici, 45.04 ° N / 18.42 ° E, 12.5.1974, 1 ♀ (leg. P. Pronk). BULGARIA: Blagoevgrad: Kresna, 41 ° 42 ′ N / 23 ° 09 ′ E, 170 m, 5.5. – 9.5.2010, 1 ♀, 2 ♂ (leg. Pacholatko); Burgas: Slancev brjag, 18. – 30.5.1989, 2 ♀ (leg. M. Halada); Chaskowo: Charmandli, 20.5.1978, 1 ♀ (leg. M. Kocourek); Kardschali: Rodopi, Monchilgrad, 41 ° 31 ′ N / 25 ° 25 ′ E, 400 m, 18.5.2012, 1 ♀ (leg. Pacholatko); Plovdiv: Rodopi, Hrabrino, 20.5.1997, 1 fv (leg. Z. Pedr); Sliven: Ichera, 6.1962, 1 ♂ (leg. M. Kocourek); Stara Zagora: Rodopi, Galabovo, 8.6.1996, 1 ♀ (leg. Z. Pedr); Vratsa: Trakia, Volvodovo, 18.5.1996, 2 ♀, 1 ♂ (leg. Z. Pedr). CROATIA: Brod-Posavina: Ljupina, 45 ° 15 ′ N / 17 ° 22 ′ E, 14.5.1981, 1 ♂ (leg. H. Rausch, F. Ressl). CZECH REPUBLIC: Jihomoravsky kraj: Moravia, Mikulov, Kopecek, 30.6.1988, 1 ♀ (leg. Z. Padr). FRANCE: Alpes-de-Haute-Provence: Sisteron, 25.4.1960, 1 ♂ (leg. H. Wiering); Alpes-Maritimes: Nizza, Castagnier, 600 m, 7.5.1992, 1 ♀ (leg. S. Risch); Bouches-du-Rhône: Crau, Vergiere, 28.4.1991, 1 ♂ (leg. C. Schmid-Egger); Gard: Uzès, 27.4.1976, 1 ♂ (leg. H. Wiering); Haute-Garonne: Toulouse, 5.1931, 1 ♂ (leg. Gasche); Hérault: Agde, Vias, 4.5.1997, 5 ♀ (leg. M. Mucka); Lot: Le Montat, 14. - 19.5.1986, 1 ♀ (leg. A. D. J. Meeuse); Pyrénées-Orientales: Villelongue, 400 m, 25.5.1996, 1 ♀ (leg. H. Wiering); Var: Montmayon, 350 m, 14.5.2004, 1 ♂ (leg. Namur); Vaucluse: Lourmarin, 250 m, 21.5.2004, 1 ♀ (leg. A. Müller). GREECE: Aegean Islands: Lesvos, Aspropotamos, 39.286 ° N / 26.3682 ° E, 11.4.2012, 1 ♂ (leg. A. Chroni); Rhodes, Lindos, 23.4.1970, 1 ♂ (leg. H. Teunissen); Samos, Karlovasi, 26.4.1977, 1 ♀ (leg. H. Teunissen); Samothrace, Alonia, 40.4684 ° N / 25.5191 ° E, 23.4.2012, 1 ♂ (leg. M. de Courcy); Thasos, Theologos, 40.6538 ° N / 24.6788 ° E, 11.4.2012, 1 ♂ (leg. M. de Courcy); Attica: Athens, Papagos, 37.982 ° N / 23.8106 ° E, 29.3.2012, 1 ♂ (leg. E. Papas); Central Greece: 30 km S Lamia Bralos, 10.5.2005, 17 ♀ (leg. J. Halada); Central Macedonia: Athos, 180 m, 27.4.1987, 1 ♀ (leg. S. Blank); Crete: Rethimno, 3 km NW Gonies, 26.4.1985, 1 ♂ (leg. R. Leys); Eastern Macedonia and Thrace: Sidironeron, 20 km N Drama, 640 m, 25. – 30.5.1987, 2 ♂ (leg. P. Thomas); Epirus: Preveza, Parga, 140 m, 22.4.2002, 1 m (leg. R. Neumeyer); Ionian Islands: Kephalonia, 1.5. – 4.5 km W Dimisianata, 150 m, 15.4.1992, 1 ♂ (leg. S. Blank); Korfu, Aghii Deka, 5.1978, 1 ♂ (leg. H. Teunissen); Lefkada, Khortata, 900 m, 20.4.1977, 2 ♂ (leg. K. Guichard); Peloponnese: Mistras near Sparta, 17.4.2000, 1 ♀ (leg. W. Arens); Thessaly: SE Mount Mavrovuni, 35 km N Volos, 5.5.2005, 2 ♂ (leg. J. Halada); Western Greece: Andritsena, Vassae, 30.5.1998, 1 ♀ (leg. W. Arens); Western Macedonia: Florina, 680 m, 5.5.1971, 1 ♀ (leg. J. v. d. Vecht). IRAN: Fars: Dast Arjan, 29.552 ° N / 51.942 ° E, 2260 m, 4.5.2016, 1 ♀ (leg. M. Kafka); Ilam: Abda Man Dinar Gaouh, 32.915 ° N / 47.301 ° E, 1830 m, 12.5.2016, 2 ♀ (leg. M. Kafka); Kohgiluyeh and Boyer-Ahmad: Likak Gach Boland, 30.993 ° N / 50.148 ° E, 1640 m, 7.5.2016, 1 ♀ (leg. M. Kafka); Lorestan: Dorud, Lanjabad, 33.419 ° N / 48.986 ° E, 960 m, 10.5.2016, 1 ♀ (leg. M. Kafka). IRAQ: Dahuk: Mount Gara, 1912 m, 37.015833 ° N / 43.350556 ° E, 11.5.2023, 4 ♀, 5 ♂ (leg. D. Baiocchi). ITALY: Liguria: Levanto, 21. – 25.4.1992, 1 ♀ (leg. A. Müller); Lombardia: Pusiano, 11.4.1948, 1 ♀, 1 ♂ (leg. A. Nadig); Puglia: Gargano, Mt. S. Angelo, 400 – 700, 27.5.1993, 1 ♀ (leg. A. Müller); Sardinia: Cala Gonone, 40.266 ° N / 9.628 ° E, 30 m, 29.4.2018, 1 ♂ (leg. D. Bénon). HUNGARY: Central Hungary: Bakony, Zirc, 24. – 26.5.1991, 1 ♂ (leg. N. Mohr); Central Transdanubia: Balatonfüred, 2 km S Tihany, 30.5.1992, 1 ♀ (leg. C. Schmid-Egger); Northern Great Plain: Bihardancshazza, 15 km W Berettyoujfalu, 12.6.1995, 1 ♀ (leg. L. Blommers); Southern Transdanubia: Mecsek, Pécs, 31.5.1991, 2 ♂ (leg. N. Mohr). MONTENEGRO: Budva: Sveti Stefan, 3. 9.5.1974, 1 ♀ (leg. P. Witzgall). NORTH MACEDONIA: East: Stip, 6.5.1904, 1 ♀ (leg. Meyer); Pelagonia: Pelister, Baba mountains, 6.6.1972, 1 ♂ (leg. H. Teunissen); Southeast: Gevgelija, 26.4.1957, 1 ♀ (leg. Gines). ROMANIA: Alba: Rimetea, 46 ° 27.6 ′ N / 23 ° 34.15 ′ E, 550 – 600 m, 30.5.2007, 1 ♂ (leg. Z. Pedr) Caras-Severin: Cozia, W Turnu Severin, 26.5.2002, 2 ♀ (leg. M. Halada); Mehedinti: Orsova at route Cozla-Bigar, 25.5.2002, 1 ♂ (leg. M. Snizek). SERBIA: Belgrade: Resnik, 8.5.1936, 1 ♂ (leg. Martino). SLOVAKIA: Nitra: Sturuvo env., 6.5.1965, 1 ♀ (leg. M. Kocourek). SLOVENIA: Podravska: Maribor, Varazdin, 275 m, 26.4.1960, 3 ♂ (leg. K. Guichard); Primorsko-notranjska: Istria, Portoroz, 7.5.1904, 1 ♀ (leg. F. Parré); Savinjska: Podcetrtek, 26.6.1938, 1 ♀ (leg. Stöcklein). SPAIN: Alicante: Petrer, 38.45892 ° N / 0.77740 ° W, 407 m, 2.4.2017, 1 ♀ (leg. H. Schwenninger); Balearic Islands: Mallorca, Sóller, 22.4. – 5.5.1976, 1 ♂ (leg. B. J. Lempke); Salamanca: Mozarbez, 40 º 50 ′ 21 ′′ N / 5 º 38 ′ 27 ′′ W, 12.05.2022, 1 ♀ (leg. J. Smit); Segovia: Rio Peces, Revenga, 1165 m, 9.6.2012, 1 ♀ (leg. J. Ortiz-Sánchez). TURKMENISTAN: Balkan Region: Ai-dere, 24.4. – 1.5.1986, 5 ♀, 1 ♂ (leg. E. Budris).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC5FFB5FF56FBF15852FE3A.taxon	distribution	Distribution. Southern, southern Western, southern Central and southern Eastern Europe (Portugal, Spain, France, Italy including Sardinia and Sicily, southern Switzerland, Austria, southern Czech Republic, Slovakia, Hungary, Romania, Slovenia, Croatia, Bosnia and Herzegovina, Serbia, Montenegro, North Macedonia, Bulgaria, Greece including Aegean Islands, Crete and Ionian Islands), Turkey, Caucasus (Azerbaijan, Georgia), northern Iraq, Iran and southwesternmost Turkmenistan. Pollen hosts. Oligolectic on Ranunculus (Ranunculaceae) (Sedivy et al. 2008). Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC7FFB8FF56FE1559AEFD36.taxon	materials_examined	Holotype. ISRAEL AND PALESTINE: Northern District: Mount Hermon, 3 km N Majdal al-Shams, 33 ° 17 ′ 35 ′′ N / 35 ° 45 ′ 33 ′′ E, 1500 m, 4.5.2010, 1 ♀ (leg. C. Sedivy, C. Praz). Deposited in the Entomological Collection of ETH Zurich Paratypes. ISRAEL AND PALESTINE: Central District: Nes Tsiyona, 31.928 ° N / 34.78 ° E, 4.3.2009, 1 ♀ (leg. A. Dorchin); Haifa District: Mount Carmel, 27.3.2000, 1 ♂ (leg. M. Török); Mount Carmel, En Hod, 32 ° 41.97 ′ N / 34 ° 58.56 ′ E, 80 m, 2.4. – 16.4.2000, 3 ♀ (leg. S. Roberts); Mount Carmel, Etzbah, 32 ° 42 ′ 41 ′′ N / 34 ° 54 ′ 74 ′′ E, 180 m, 5.4.1999, 2 ♀ (leg. S. Roberts), 3.4. – 4.4.2000, 6 ♀, 2 ♂ (leg. S. Roberts); Mount Carmel, Haibar, 300 m, 5.4.2000, 3 ♂ (leg. S. Roberts); Mount Carmel, Kedumim, 200 m, 10.4.2000, 1 ♀, 1 ♂ (leg. S. Roberts); Mount Carmel, Mitla, 300 m, 6.4. – 17.4.2000, 2 ♀, 1 ♂ (leg. S. Roberts); Northern District: Mount Hermon, 19.4.1988, 6 ♂ (leg. M. Kraus); 20 km NE Qiryat Shemona, Hermon Cableway, 33 ° 18 ′ N / 35 ° 46 ′ E, 16.5.1996, 1 ♀ (leg. M. Hauser); Humra Hill, 12.3.2009, 1 ♂ (leg A. Dorchin); Bet Rimon, N Kafr Kana, 7.5.2019, 1 ♀ (leg. T. Kwast); Southern District: Negev, 15 km SE Dimona, 21.3.1990, 1 ♀ (leg. R. Leys); Negev, 5 km SE Yeroham, 21.3.1990, 1 ♂ (leg. R. Leys); Avedat, 10.4.1990, 2 ♀ (leg. K. Warncke); Wadi Hevyon, 13 km E Yeroham, 12.4.1990, 1 ♀ (leg. K. Warncke); Har Ramon, 30 km SW Mizpe Ramon, 13.4.1990, 2 ♀, 1 ♂ (leg. K. Warncke). JORDAN: Irbid: Tall Al Arbatin, 20 km S North Shuna, 19.4.1996, 4 ♀ (leg. M. Halada); North Shuna, 29. - 30.4.1996, 3 ♀ (leg. M. Halada); Jerash: 10 km N Jerash, 19. – 20.4.2002, 8 ♀ (leg. M. Snizek). LEBANON: North: Horch Ehden, Nabeh Jouit, 34.31608 ° N / 35.98269 ° E, 1336 m, 24.4.2019, 1 ♀, 2 ♂ (leg. M. Boustani); Horch Ehden, Trail 1, 34.30972 ° N / 35.98939 ° E, 1534 m, 2.5.2017, 1 ♂ (leg. M. Boustani). Deposited in the Entomological Collection of ETH Zurich, the Oberösterreichisches Landesmuseum Linz and the Steinhardt Museum of Natural History Tel Aviv. Additional material. ISRAEL AND PALESTINE: Central District: Haruzim NR, 32 ° 13 ′ 47 ′′ N / 34 ° 51 ′ 35 ′′ E, 35 m, 30.3.2009, 1 ♀, 1 ♂ (leg. A. Dorchin), 17.02.2010, 1 ♂ (leg. A. Dorchin); Bet Hanan, 6.3.2009, 3 ♂ (leg. A. Dorchin); 1.3 km SE Bet Hanan, 31 ° 55 ′ 43 ′′ N / 34 ° 45 ′ 52 ′′ E, 35 m, 3.3.2010, 1 ♂ (leg. A. Dorchin); 0.8 km S Bet Hanan, 31 ° 55 ′ 41 ′′ N / 34 ° 46 ′ 20 ′′ E, 34 m, 3.3. – 4.3.2010, 2 ♀ 15 ♂ (leg. A. Dorchin); 1.1 km SE Bet Hanan, 31 ° 55 ′ 43 ′′ N / 34 ° 46 ′ 00 ′′ E, 30 m, 3.3. – 4.3.2010, 3 ♂ (leg. A. Dorchin); Sharon Plain, Nahal Alexander, 32 ° 24.331 ′ N / 34 ° 53.042 ′ E, 10.3.2019, 1 ♀, 1 ♂ (leg. K. Levy), 24.3.2020, 2 ♀ (leg. K. Levy), 31.3.2021, 2 ♂ (leg. K. Levy); Sharon Plain, Tel Yizhaq NR, 32 º 14 ′ 34 ′′ N / 34 º 51 ′ 53 ′′ E, 20 m, 16.3.2011, 1 ♂ (leg. A. Dorchin); 1.75 km SW Gan Soreq, 31 ° 56 ′ 06 ′′ N / 34 ° 44 ′ 34 ′′ E, 18 m, 7.3.2010, 1 ♀ (leg. A. Dorchin); Central Coastal Plain, Bené Deror, 7.3.2012, 3 ♂ (leg. O. Afik); Central Coastal Plain, Qadima, 3.2012, 1 f, 4 ♂ (leg. O. Afik); Central Coastal Plain, Zur Moshe, 13.3.2012, 2 ♂ (leg. O. Afik); Geva′ot HaKhurkhar NP, 31 ° 56 ′ 08 ′′ N / 34 ° 47 ′ 10 ′′ E, 50 – 60 m, 23.3. – 1.4.2010, 2 ♀ (leg. A. Dorchin); Iris Ha′Argaman NR, 31 ° 55 ′ 54 ′′ N / 34 ° 45 ′ 11 ′′ E, 29 m, 2.3.2010, 2 ♀ (leg. A. Dorchin); Judean Foothills, Ya′ar Adolam, 8.4.2010, 1 ♀ (leg. T. Koznichki), 20.4.2011, 2 ♀ (leg. T. Koznichki), 3.4.2013, 1 ♀ (leg. Y. Berner), 25.3.2015, 1 ♂ (leg. T. Chaprazaro); Nahshon junction, 9.3.2017, 9 ♂ (leg. T. Roth); Nes Tsiyona, 31.928 ° N / 34.78 ° E, 4.3. – 31.3.2009, 2 ♀, 6 ♂ (leg. A. Dorchin), 13.3.2015, 1 ♂ (leg. G. Pisanty); Shfela, Shiller, 25.0.2021, 1 ♂ (leg. Y. Halevi); Ya′ar Kedoshim, 7.3. – 30.3.2014, 2 ♀, 2 ♂ (leg. N. Shamir), 15.4. – 16.4.2017, 2 ♀ (leg. Y. Farago); Haifa District: Daliyat el-Karmil S Haifa, 5.7.1997,1 ♀ (leg. J. Rozen); 1.3 km N Tiv′on, 32 ° 44 ′ 14 ′′ N / 35 ° 07 ′ 55 ′′ E, 163 m, 23.3.2012, 1 ♀ (leg. A. Dorchin); Kerem Maharal, 32.643 ° N / 34.981 ° E, 800 m, 3.4.2015, 1 ♀ (leg. G. Pisanty); Mount Carmel, En Hod, 32 ° 41 ′ 97 ′′ N / 34 ° 58 ′ 56 ′′ E, 80 m, 4.4.1999, 3 ♀ (leg. S. Roberts); Mount Carmel, Etzbah, 32 ° 42 ′ 41 ′′ N / 34 ° 54 ′ 74 ′′ E, 180 m, 5.4. – 9.4.1999, 6 ♀, 1 ♂ (leg. S. Roberts), 3.4. – 4.4.2000, 4 ♀, 4 ♂ (leg. S. Roberts); Mount Carmel, Kedumim, 200 m, 10.4.2000, 5 ♂ (leg. S. Roberts); Mount Carmel, Mitla, 300 m, 6.4. – 17.4.2000, 5 ♀ (leg. S. Roberts); Mount Carmel, Quarry, 23.4.2000, 1 ♂ (leg. M. Török); Mount Carmel, Yagur, 26.3.2011, 1 ♂ (leg. G. Pisanty); Mount Carmel, Ramat haNadiv, 22.3.2012, 1 ♀ (leg. T. Shapira), 26.2. – 2.4.2013, 2 ♀, 2 ♂ (leg. T. Shapira); Jerusalem District: Shoresh, 31.79252 ° N / 35.06936 ° E, 680 m, 6.4. – 7.4.2012, 1 ♀, 1 ♂ (leg. J. S. Ascher, A. Payne); Judean Foothills, Harel, 18.3.2011, 1 ♂ (leg. G. Pisanty); Judean Foothills, Ya′ar Yish′i, 26.2.2013, 1 ♂ (leg. Y. Berner), 8.5.2015, 2 ♀ (leg. T. Chaprazaro); Netiv Halamed Heh, 27.3.2017, 1 ♂ (leg. T. Roth); Northern District: Tiberias, - 200 m, 22.3.1975, 1 m (leg. K. Guichard); 10 km E Nahariyya, 9.4.1988, 1 ♂ (leg. R. Leys); Humra Hill, 12.3.2009, 1 ♀ (leg A. Dorchin); 600 m E Alonim, 32 º 43 ′ 11 ′′ N / 35 º 09 ′ 17 ′′ E, 138 m, 21.3.2011, 1 ♀ (leg. H. Ztohari); Yiftach, 17.4.2014, 1 ♀ (leg. O. Winberger), 30.3.2016, 2 ♂ (leg. O. Winberger); Ramot Naftali, 5.4.2015, 1 ♂ (leg. O. Winberger); Yir′on, 8.4.2015, 1 ♂ (leg. O. Winberger), 30.3.2016, 2 ♀ (leg. O. Winberger); Gush Halav, 31.3.2016, 1 ♀ (leg. O. Winberger); 1 km SW Ziv′on, 33.019 ° N / 35.407 ° E, 5.4.2016, 2 ♀ (leg. G. Pisanty); Malkiya, 19.4.2016, 1 ♀ (leg. O. Winberger); Southern District: Judean Foothills, Beit Govrin, 28.3.2010, 1 ♀ (leg. G. Pisanty); Judean Foothills, Park Britannia, 15.4.2011, 3 ♀ (leg. T. Koznichki), 13.3.2013, 1 ♂ (leg. Y Berner), 26.3. – 6.5.2015, 6 ♀ (T. Chaprazaro), 24.3. – 14.4.2016, 2 ♀ (leg. T. Chaprazaro); Judean Foothills, Lakhish, 21.3. – 10.4.2012, 1 ♀, 7 ♂ (leg. T. Shapira), 6.3. – 8.4.2013, 14 ♀, 8 ♂ (leg. T Shapira); 2 km E Lakhish, 31.557 ° N / 34.870 ° E, 4.3. – 19.3.2016, 1 ♀, 9 ♂ (leg. G. Pisanty); 3 km NE Lakhish, 31.578 ° N / 34.870 ° E, 26.2. – 23.3.2016, 3 ♀, 6 ♂ (leg. G. Pisanty); Beit Nir, 31.626900 ° N / 34.884633 ° E, 11.3.2018, 2 ♀ (leg. T. Roth); Tel Zafit, 31.682911 ° N / 34.848353 ° E, 31.3.2018, 1 ♂ (leg. T. Roth); Tel Aviv District: Tel Aviv University, Botanical Garden, 32 ° 06 ′ 50 ′′ N / 34 ° 48 ′ 31 ′′ E, 2. – 5.04.2012, 1 ♂ (leg. J. S. Ascher); West Bank: Tell Jericho, - 300 m, 12.2.1986, 1 ♂ (leg. A. W. Ebmer); Nabi Musa Road, 22.2.2014, 1 ♂ (A. Gotlieb). JORDAN: Ajloun: Ajloun env., 32 ° 19 ′ N / 35 ° 43 ′ E, 2006, 1 ♀ (leg. F. Kantner); Irbid: S Irbid, 13.4.2009, 1 ♀ (leg. M. Snizek); Jerash: Alhuna SW Jerash, 12.4.2009, 1 ♀, 1 ♂ (leg. M. Snizek); NE Rajib W Jerash, 14.4.2009, 1 ♀ (leg. M. Snizek). LEBANON: Beqaa: Beqaa valley, Mansourah, Aana village, 33.691 ° N / 35.7581 ° E, 900 m, 2.4.2023, 2 ♀ (leg. T. Wood); 5 km S Rachaiya, Mount Hermon nature reserve, 33.4586 ° N / 35.8395 ° E, 1500 m, 8.4.2023, 1 ♂ (leg. T. Wood); North: Horch Ehden, Nabeh Jouit, 34.31608 ° N / 35.98269 ° E, 1336 m, 24.4.2019, 1 ♂ (leg. M. Boustani); Horch Ehden, Trail 1, 34.30972 ° N / 35.98939 ° E, 1534 m, 2.5.2017, 1 ♂ (leg. M. Boustani). SYRIA: Al-Quneitra: Golan Heights, Nahal Zawitan, 32.960 ° N / 35.690 ° E, 209 m, 24.4.2019, 1 ♀ (leg A. Dorchin).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC7FFB8FF56FE1559AEFD36.taxon	diagnosis	Diagnosis. C. levantense is in both sexes very similar to the two other representatives of the C. emarginatum species group. The females differ from both C. edentulum and C. emarginatum by i) the shorter body length, which is usually less than 8 mm, ii) the apical margin of the labrum, which has a small triangular to semicircular incision (Fig. 3), and iii) the mandible, which bears three teeth almost equidistant from each other, with the basalmost tooth being of about the same size as the second outermost tooth (Fig. 4). The males can be distinguished from the other two species of the C. emarginatum group by the following combination of characters: i) body length at most 8 mm, ii) vertex short with distance between inner margins of lateral ocelli being about as long as distance between posterior margin of lateral ocellus and occipital margin (Fig. 6), iii) tibial spur of fore leg apically usually slightly emarginate resulting in two small lobes (Fig. 7), iv) minimal distance between inner margins of the two patches of short black thorns on sternum 3 about the same as maximum diameter of one patch or slightly shorter (Fig. 9), and v) long hairs protruding from apical part of gonoforceps whitish.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC7FFB8FF56FE1559AEFD36.taxon	description	Description. FEMALE (Fig. 1): Body length 6 – 8 mm. Head: Head 1.0 - 1.075 × as long as wide. Distance between posterior margin of lateral ocellus and occipital margin 1.5 - 1.7 × as long as ocellar diameter. Clypeus slightly convex, its apical margin laterally protruding and medially straight with several small triangular teeth; punctation of clypeus laterally moderately dense with interspaces reaching the diameter of one to two punctures, on narrow median and apical zone distinctly more scattered and finer. Labrum flat over almost its entire length, its apical margin medially with small but distinct triangular to semicircular incision (Fig. 3). Mandible with three teeth, whose tips are almost equidistant from each other and whose basalmost tooth is of about the same size as the second outermost tooth (Fig. 4). Proboscis short (Fig. 1), reaching in repose not till base of fore coxa; second segment of labial palpus about 3 × as long as first segment and about 0.5 × as long as compound eye. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially about as long as metanotum to slightly longer, flat, not bordered by raised ridge along its entire posterior margin and with rather fine longitudinal carinae (Fig. 5). Metasoma: Marginal zones of terga 1 – 4 (5) with dense and short white hair bands (Fig. 1), which are usually not interrupted in fresh specimens. Terga 2 – 3 not constricted at base. Scopa white, its hairs not plumose (Fig. 1). MALE (Fig. 2): Body length 6 – 8 mm. Head: Head 0.925 – 0.975 × as long as wide. Distance between posterior margin of lateral ocellus and occipital margin 1.25 – 1.5 × as long as ocellar diameter and between inner margins of lateral ocelli about as long as distance between posterior margin of lateral ocellus and occipital margin (Fig. 6). Hypostomal area without tubercles or tooth-like projections. Proboscis short (Fig. 2), reaching in repose not till base of fore coxa; second segment of labial palpus about 3 × as long as first segment and about 0.5 × as long as compound eye. Anterior side of antennal segments (5) 6 - 12 (13) yellowish-red. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially about as long as metanotum to slightly longer, flat, not bordered by raised ridge along its entire posterior margin and with rather fine longitudinal carinae. Tibial spur of fore leg apically usually slightly emarginate resulting in two small and weakly separated lobes (Fig. 7). Metasoma: Marginal zones of terga 1 – 5 with very loose and long white hair bands (Fig. 2), which are widely interrupted on terga 1 – 3. Terga 2 – 3 weakly constricted at base. Tergum 7 basally with oval pit and apically with two teeth, which are about as long as basally wide to slightly longer, apically truncate and separated from each other by semicircular incision twice as wide as to slightly longer than tooth width (Fig. 8). Median projection of sternum 2 large, half-elliptical, concave and distinctly rising towards posterior margin, its anterior margin rounded in ventral view and slightly overhanging concave anterior surface in lateral view (Fig. 9). Sternum 3 with two lateral, longish-oval to narrowly kidney-shaped patches of short black thorns (Fig. 9); minimal distance between inner margins of these two thorn patches about as long as maximum diameter of one patch or slightly shorter. Sternum 4 densely covered with whitish pilosity, which surpasses apical margin and is lateroapically curled downwards. Apical margin of sternum 5 with a single row of long yellowish bristles. Sternum 6 roughly quadrangular in shape, its apical half polished, very sparsely haired and impunctate. Gonoforceps with long and whitish hairs protruding from its apical part.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC7FFB8FF56FE1559AEFD36.taxon	distribution	Distribution. From northern Lebanon over southern Syria and northern Jordan to southern Israel (Fig. 74). Pollen hosts. Polylectic; pollen sources known so far include Cistaceae, Ranunculaceae, Brassicaceae, Resedaceae and Zygophyllaceae (Sedivy et al. 2008, as Chelostoma species 3). Flower records: Diplotaxis erucoides (Brassicaceae), Caylusea hexagyna (Resedaceae) (label records).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFC7FFB8FF56FE1559AEFD36.taxon	etymology	Etymology. The species epithet refers to the small distribution area restricted to the Levant, which is the geographic area that ranges from southernmost Turkey to the Sinai Peninsula.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCAFFB9FF56FBF15B24FA2E.taxon	description	Literature records. Outside Europe: GEORGIA: Kvemo Kartli, Samzche-Dschawachetia, Tbilisi (Kirkitadze and Japoshvili 2015). TURKEY: Ankara, Artvin, Bolu, Erzurum, Konya, Samsun, Yozgat (Özbek 2011). New records. Outside Europe: ARMENIA: Tawusch: Dilidschan, 5.6.1998, 1 ♂ (leg. Beenai). GEORGIA: Kvemo Kartli: Manglisi, 14.6.2015, 1 ♂ (leg. M. Snizek).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCAFFB9FF56FBF15B24FA2E.taxon	distribution	Distribution. Almost entire Europe (except for Iceland, Ireland, Scotland, Fennoscandia north of 63 ° northern latitude as well as all Mediterranean islands, such as Balearic Islands, Corsica, Sardinia, Sicily, Crete or Cyprus), Turkey and Caucasus (Armenia, Georgia). The species is known from the following European countries: Albania, Andorra, Austria, Belarus, Belgique, Bosnia and Herzegovina, Bulgaria, Croatia, Czech Republic, Denmark, Estland, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Moldova, Netherlands, Norway, Poland, Portugal, Romania, central and southern European Russia, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Ukraine including Crimea, United Kingdom (Reverté et al. 2023). Pollen hosts. Oligolectic on Ranunculus (Ranunculaceae) (Westrich 1989; Sedivy et al. 2008). The females collect the pollen of Ranunculus by rapidly tapping their metasomal scopa against the anthers in a sideways body posture. To supply a single brood cell, the entire pollen content of about ten flowers of Ranunculus acris is needed (Müller et al. 2006). In a capture-recapture study, pollen-collecting females exploited Ranunculus stands up to 650 m away from the nest, crossed forests up to 480 m wide and overcame differences in altitudes of more than 130 m on their flights between nest and feeding habitats; the latter seems particularly impressive as the females had to fly uphill 10 – 15 times a day to reach the nest with a full load of pollen, which can account for up to a seventh of their entire body weight (Zurbuchen et al. 2010). In very rare and exceptional cases, the females were observed to collect pollen also on other plants, such as Fragaria and Rosa (Rosaceae) or Stellaria (Caryophyllaceae) (Käpylä 1978; Schulze et al. 2012). In fact, experiments showed that the larvae can also develop on pollen of Campanula (Campanulaceae) and Brassica (Brassicaceae), suggesting a certain flexibility to use other pollen sources when Ranunculus flowers are not available; in contrast, development on the pollen of Tanacetum (Asteraceae) proved to be impossible (Praz et al. 2008). Nesting biology. C. florisomne nests in narrow linear cavities with a diameter of 3 – 5.5 mm, such as insect burrows in dead wood, hollow plant stems (e. g. Phragmites), artificial borings in wood and stems or more rarely in abandoned nests of aculeates in clay walls or in glass tubes (Bonelli 1967, 1968; Brechtel 1986; Käpylä 1978; Maréchal 1933; Rozen & Praz 2016; Ruszkowski et al. 1995; Van Lith 1957; Westrich 1989). The nests contain 1 – 10, in exceptional cases up to 27 linearly arranged brood cells, which are often interrupted by short empty spaces. An empty vestibule is usually present between the outermost brood cell and the nest plug. The partitions between the brood cells and the nest plug consist of mud, which is mixed with nectar and possibly also salivary secretions as a binding agent. The construction of the thin cell partitions requires only 3 – 5 material transport flights and takes only a few minutes. In contrast, several hours may be needed to build the thick nest plug, in which small pebbles, sand grains, small snail shells or other particles are typically embedded on its outside. C. florisomne overwinters as an uncoloured or more rarely as a coloured pupa in a self-spun cocoon within the brood cell. Metamorphosis to the imaginal stage takes place after the first winter with some of the individuals undergoing a twoyear development. Reported larval parasites are Chrysis ignita (L.), Chrysura austriaca (Fabricius) and Trichrysis cyanea (L.) (Hymenoptera, Chrysididae), Eurytoma nodularis Boheman (Hymenoptera, Eurytomidae), Melittobia acasta Walker (Hymenoptera, Eulophidae), species of Ephialtes and Townesia (Hymenoptera, Ichneumonidae) and Trichodes alvearius (Fabricius) (Coleoptera, Cleridae) (Maréchal 1933; Berland & Bernard 1938; Van Lith 1957; Westrich 1989). Known food parasites are Monosapyga clavicornis (L.) and Sapyga quinquepunctata (Fabricius) (Hymenoptera, Sapygidae) as well as Gasteruption jaculator (L.) (Hymenoptera, Gasteruptionidae).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCAFFB9FF56FBF15B24FA2E.taxon	description	Male mating behaviour. The males patrol the flowers of Ranunculus in rapid flight in search of females; at the beginning of the flight period, they also visit (potential) nesting sites in order to mate with hatching females (Käpylä 1978; Westrich 1989). The males possess a dense tuft of short whitish to yellowish hairs on the lowermost part of the genal area near the mandibular base; this specialised pubescence likely plays a role in mating behaviour, as it is often soaked with a liquid of unknown origin, which might serve to mark flight areas or be used for inter-sexual communication during courtship and mating. Note. A male from the province Bolu in Turkey (“ Bolu lake env., 28.4.1994, leg. M. Halada ”) is morphologically very close to C. florisomne except for the comb of long yellowish bristles along the apical margin of sternum 5, which covers only the central half of the sternal width rather than the entire sternal width as in C. florisomne. This male is tentatively regarded as an aberrant specimen of C. florisomne until further material from northwestern Turkey is available.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCBFFB9FF56FA215852F874.taxon	distribution	Distribution. Known so far only from the Nebrodi and Madonie mountains in northern Sicily. Pollen hosts. Polylectic; pollen sources known so far include Ranunculus (Ranunculaceae) and Helianthemum (Cistaceae) (Müller 2012). Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCCFFBFFF56FDE45B44FEAE.taxon	description	New records. FRANCE: Savoie: Valle de Charmy, 1.7.1988 (leg. C. de Jong).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCCFFBFFF56FDE45B44FEAE.taxon	distribution	Distribution. In mountaineous regions in southwestern, central and southeastern Europe usually at elevations between 1000 and 2000 m (Westrich 1993): Cantabrian Mountains (Spain), Alps (Austria, France, Italy, Liechtenstein, Slovenia, Switzerland), Dinaric Alps (Kosovo), Banat mountains (Romania), Pindos, Akarnanika ́ and Panaitoliko mountains (Greece). The Romanian record from Mehadia by Schletterer 1889 was questioned by Westrich (1993), who suspected a possible confusion with C. transversum. However, C. transversum has never been recorded from Romania (see below) and Mehadia is located in the Banat mountains, which rise up to 1450 m, so that the occurrence of C. grande in this southern part of the Western Romanian Carpathians seems probable. In contrast, the records of C. grande by Banaszak & Dochkova (2014) from the Danubian plain and the Upper Thracian Plain in northern and central Bulgaria are certainly erroneous given the low altitude of these primarily arable landscapes. Similarly, the Bulgarian record of C. grande from western Stara planina (Atanassov 1972 a, b) is most probably based on a misidentification, since the single female was collected on Medicago sativa in an agricultural field at an elevation of about 500 m, all of which is highly improbable for this mountaineous species that is specialised on Dipsacoideae. The records of C. grande from the Nur Mountains in south-central Turkey (Friese 1921) and from Azerbaijan (Maharramov et al. 2014) are also highly unlikely and probably refer to C. lucens or C. scabiosae. Pollen hosts. Oligolectic on Dipsacoideae (Amiet et al. 2004; Sedivy et al. 2008; Westrich 1993). Main pollen hosts are species of Knautia and Scabiosa, such as K. arvensis, K. dipsacifolia and S. triandra. Nesting biology. C. grande nests in linear cavities of about 6 mm in diameter, primarily in insect burrows in dead wood, but also in hollow bamboo stems if these are offered as nesting sites (Frey-Gessner 1880; Friese 1923; Westrich 2002). The nests discovered so far contained an empty vestibule behind the nest plug followed by 3 – 4 linearly arranged brood cells. The partitions between the brood cells and the nest plug consist of mud, which is mixed with small pebbles of 0.5 – 2 mm diameter, part of which are deeply embedded in the mud matrix. C. grande overwinters as prepupa in a self-spun cocoon within the brood cell. Metamorphosis to the imaginal stage takes place after the second or third winter resulting in a development period of two to three years. Known brood parasites are Trichodes apiarius (L.) (Coleoptera, Cleridae) and Sapyga similis (Fabricius) (Hymenoptera, Sapygidae) (Westrich 2002).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCCFFBFFF56FDE45B44FEAE.taxon	description	Male mating behaviour. The males patrol the flower heads of Knautia and Scabiosa in rapid flight in search of females.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCDFFBFFF56FEA05EBDFAF8.taxon	description	New records. BULGARIA: Blagoewgrad: Melnik, 4.6.1984, 1 ♀, 1 ♂ (leg. B. Karas); Chaskowo: 30 km SW Svilengrad, 41 ° 43 ′ N / 26 ° 02 ′ E, 550 m, 21.06.08, 1 ♀ (leg. M. Halada, Z. Halada). GREECE: Aegean Islands: Rhodes, Archangelos, 100 m, 8.5.2005, 1 ♀ (leg. A. Müller); Samos, Manolates 25.4.1977, 1 ♂ (leg. H. Teunissen). ISRAEL AND PALESTINE: Haifa District: Yagur, 32.74 ° N / 35.07 ° E, 24.4.2015, 1 ♀ (leg. G. Pisanty); Northern District: Yiftah, 30.3.2016, 1 ♂ (leg. O. Winberger). JORDAN: Ajloun: 10 km N Ajloun, 23.4.2007, 1 ♀, 2 ♂ (leg. C. Praz, C. Sedivy, A. Müller). SYRIA: Al-Quneitra: Golan Heights, Nahal Zawitan, 32.945 ° N / 35.689 ° E, 168 m, 23.4.2019, 1 ♀ (leg. A. Dorchin). TURKEY: Antalya: 15 km E Kumluca, 36 ° 23.652 ′ N / 30 ° 24.201 ′ E, 540 m, 28.5.2002, 1 ♀ (leg. B. Degen); Denizli: Pamukkale, 1.6.1966, 1 ♀ (leg. J. Schmidt); Isparta: Eğirdir, Kovada Gölu, 22.5.1988, 2 ♂ (leg. N. Mohr); Manisa: 35 km SSE Salıhlı, 38 ° 20 ′ N / 28 ° 24 ′ E, 900 m, 30.6.2006, 1 ♀ (leg. J. Halada); Mersin: Uzuncaburç, 30 km N Silifke, 28.5.1996, 3 ♀ (leg. M. Halada); Muğla: Bafa lake, 19.4.1996, 3 ♂ (leg. P. Hartmann).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCDFFBFFF56FEA05EBDFAF8.taxon	distribution	Distribution. Bulgaria, Greece (Aegean Islands), Turkey, Levant (Syria, Lebanon, Israel and Palestine, Jordan). C. lucens has not yet been reliably recorded in mainland Greece. Pollen hosts. Oligolectic on Dipsacoideae (A. Müller personal observation), which is confirmed by A. W. Ebmer (personal communication), who observed many specimens of C. lucens exclusively visiting Scabiosa on Samos in spring 2014. Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCDFFBFFF56FEA05EBDFAF8.taxon	description	Note. C. “ lucens ” in Mavromoustakis (1951) and Varnava et al. (2020) is C. comosum Müller.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCDFFBDFF56FA535B53F9E2.taxon	materials_examined	Holotype. TURKEY: Şırnak: 19 km S Beytisebap, 1200 m, 26.6.1985, 1 ♀ (leg. M. Schwarz). Deposited in the Entomological Collection of ETH Zurich. Paratypes. IRAN: Ilam: Abda Man, Dinar Gaouh, 32.915 ° N / 47.301 ° E, 1830 m, 12.5.2016, 3 ♂ (leg. M. Kafka). TURKEY: Hakkari: 25 km SW Hakkari, 1200 m, 31.5.1980, 13.6.1981, 2 ♂ (leg. M. Schwarz, K. Warncke). Deposited in the Entomological Collection of ETH Zurich.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCDFFBDFF56FA535B53F9E2.taxon	diagnosis	Diagnosis. C. scabiosae has very long mouthparts (Fig. 10) with the second segment of the labial palpus being distinctly longer than the compound eye and the proboscis distinctly surpassing the coxa of the fore leg when folded. It shares this trait with the three representatives of the C. meronense species group and the three other representatives of the C. grande species group. The females of C. scabiosae can be separated from those of the C. meronense species group by i) the longer body length of about 10 mm, ii) the long and slender labrum, which is about 3.5 × as long as apically wide (Fig. 13), and iii) the basally distinctly constricted terga 2 – 3. They differ from the other species of the C. grande group by the following combination of characters: i) declivous apical part of clypeus bent a right angles to flat basal part (Fig. 12), only about one fourth as long and as densely punctate as basal part, ii) mandible long and slender with two apical teeth, iii) labrum about 3.5 × as long as apically wide, its mediobasal part slightly concave and laterally bordered by two narrow longitudinal swellings and its apical part flat to weakly projecting upwards (Fig. 12, 13), iv) antennal segment 3 about 1.75 × as long as wide, and v) basal area of propodeum medially almost as long as metanotum (Fig. 14). The males of C. scabiosae can be separated from those of the C. meronense species group by i) the apical margin of sternum 1, which is only shallowly emarginate, ii) the median projection of sternum 2, whose apex is not projecting over the sternal base, and i) the absence of a row of stiff yellowish bristles along the apical margin of sternum 3. They differ from the other species of the C. grande group by the following combination of characters: i) median projection of sternum 2 roof-shaped, its anterior margin straight to very slightly curved (Fig. 17), ii) sternum 3 without lateral processes (Fig. 17), iii) hairs forming loose band at apical margin of sternum 4 slightly less than half as long as membraneous appendage at apical margin of sternum 4 (Fig. 17), and iv) stepped apical part of gonoforceps on inner side without long and inwardly directed hairs (Fig. 18).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCDFFBDFF56FA535B53F9E2.taxon	description	Description. FEMALE (Fig. 10): Body length 10 mm. Head: Head about 1.1 × long as wide. Distance between posterior margin of lateral ocellus and occipital margin about 3 as long as ocellar diameter. Clypeus with medially flat basal and strongly declivous apical part; declivous apical part bent a right angles to basal part (Fig. 12), only about one fourth as long as basal part and as densely punctate as basal part with interspaces rarely exceeding the diameter of half a puncture. Labrum about 3.5 × as long as apically wide, mediobasally slightly concave, densely punctate and laterally bordered by two narrow longitudinal swellings, its apicalmost part flat to weakly curved upwards (Fig. 12, 13). Mandible long and slender with two apical teeth. Proboscis very long (Fig. 10), distinctly surpassing coxa of fore leg and almost reaching coxa of middle leg; second segment of labial palpus almost 5.5 × as long as first segment and about 1.5 as long as compound eye. Antennal segment 3 about 1.75 × as long as wide. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially almost as long as metanotum, declivous and without raised carina along its posterior margin (Fig. 14). Metasoma: Terga 2 – 3 basally distinctly constricted. Marginal zone of terga 1 – 4 with dense and short white hair bands (Fig. 10), which are not interrupted in fresh specimens. Scopa white, its hairs not plumose (Fig. 10). MALE (Fig. 11): Body length 10 – 12 mm. Head: Head about as long as wide. Distance between posterior margin of lateral ocellus and occipital margin 2.6 - 2.9 × as long as ocellar diameter. Hypostomal area with two sharp, acute and roughly triangular tooth-like projections formed by hypostomal carina in its basal half (Fig. 16). Proboscis very long, distinctly surpassing coxa of fore leg and almost reaching coxa of middle leg. Antennal segments 3 - 13 about 2 × as long as wide, their anterior sides varying in colour from almost uniformly brownish to predominantly yellowish-red. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially slightly to significantly shorter than metanotum, declivous, crossed by numerous weak longitudinal carinae of varying thickness and without raised carina along its posterior margin. Tibia of fore leg ventroapically with long spine at base of tibial spur. Tibial spur of fore leg apically prolonged into rounded tip resulting in a concave outer margin of the spur. Metasoma: Marginal zones of terga 1 – 5 (6) with loose white hair bands (Fig. 11), which are widely interrupted on terga 1 – 3. Tergum 2 basally distinctly constricted. Tergum 7 basally with roundish pit and apically with two teeth, which are roughly parallel-sided, shorter than basally wide, apically weakly rounded to truncate and separated from each other by semicircular incision of about the same width as tooth width (Fig. 15). Sternum 1 basally with weakly bilobed tubercle, its apical margin medially shallowly emarginate. Median projection of sternum 2 roof-shaped, its anterior margin straight to very slightly curved (Fig. 17). Sternum 3 basally densely covered with whitish pilosity and lateroapically with small patches of short black thorns, which are separated by a polished, almost impunctate and slightly impressed zone (Fig. 17); apical margin of sternum 3 slightly emarginate and with short membraneous appendage (Fig. 17). Apical margin of sternum 4 with large membraneous appendage that is medially divided into two flat lobes and with loose band of yellowish-white hairs, which are slightly less than half as long as membraneous appendage (Fig. 17). Apical margin of sternum 5 with single row of long, yellowish and moniliform bristles (Fig. 17). Sternum 6 roughly quadrangular in shape, its apical half polished, very sparsely haired and almost impunctate. Stepped apical part of gonoforceps on inner side almost hairless (Fig. 18).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCDFFBDFF56FA535B53F9E2.taxon	distribution	Distribution. Southeastern Turkey, northwestern Iran (Fig. 74). Pollen hosts. The only available pollen load consisted of pollen of Scabiosa, suggesting that C. scabiosae is oligolectic on Dipsacoideae as are the other species of the C. grande species group. Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCDFFBDFF56FA535B53F9E2.taxon	etymology	Etymology. The species epithet refers to the most probable pollen specialization on Dipsacoideae including Scabiosa.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCFFFA2FF56F96D5852FEF2.taxon	description	New records. GREECE: Attica: Troizen, 100 – 500 m, 29.4.2000, 1 ♀, 1 ♂ (leg. W. Arens); Central Greece: Phokis Vardoussia Mts., N Perivoli, 38 ° 33 ′ 03 ′′ N / 22 ° 06 ′ 13 ′′ E, 1020 m, 6.6.2009, 1 ♀ (leg. H. Rausch); Peloponnese: Mani, Agios Dimitrios, 20 m, 29.4.2001, 6 ♀ (leg. A. Müller); Thessaly: Meteora, 26.5.1963, 1 ♀ (leg. W. Schläfle); Western Greece: 3 km S Kato Zachlorou, 800 m, 23.5.2006, 4 ♀, 1 ♂ (leg. C. Praz, C. Sedivy).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFCFFFA2FF56F96D5852FEF2.taxon	distribution	Distribution. Mainland Greece. C. transversum has not yet been reliably recorded outside mainland Greece. Pollen hosts. Oligolectic on Dipsacoideae (Sedivy et al. 2008; Ebmer 2009). Flower records: Knautia integrifolia, Scabiosa argentea (Ebmer 2009). Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD0FFA0FF56FC615B26FB12.taxon	materials_examined	Holotype. IRAQ: Dahuk: Mount Gara, 1912 m, 37.015833 ° N / 43.350556 ° E, 11.5.2023, ♂ (leg. D. Baiocchi). Deposited in the Entomological Collection of ETH Zurich. Paratypes. TURKEY: Adıyaman: Kuyucak, 8.6.1998, 1 ♀ (leg. M. Snizek); Karadut, Nemrut Dağı, 9.6.1998, 1 ♂ (leg. M. Halada); Siirt: 5 km E Eruh, 5.6.1980, 1 ♀ (leg. K. Warncke). Deposited in the Entomological Collection of ETH Zurich.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD0FFA0FF56FC615B26FB12.taxon	diagnosis	Diagnosis. The females of C. dolichocephalum can be separated from those of the other two species of the C. meronense group by the following combination of characters: i) head 1.3 – 1.4 × as long as wide (Fig. 21), ii) third segment of labial palpus as long as fourth segment or slightly shorter, iii) basal area of propodeum medially distinctly longer than metanotum (Fig. 22), and vi) anterior surface of coxa of fore leg medially very sparsely punctate with interspaces reaching the diameter of several punctures (Fig. 23). The males differ from the two related species by the following combination of characters: i) hypostomal area with tooth-like projection of roughly triangular shape (Fig. 24), ii) genal area along lower margin of compound eye distinctly impressed and almost impunctate, iii) third segment of labial palpus as long as fourth segment or slightly shorter, iv) antennal segments 5 – 12 asymmetrical and shorter than wide to as long as wide (Fig. 25), v) last antennal segment roundish and distinctly button-like (Fig. 25), vi) anterior side of antennal flagellum predominantly yellowish to yellowish-white (Fig. 25), vii) basal area of propodeum medially distinctly longer than metanotum, viii) anterior margin of median projection of sternum 2 with projecting flat lamella (Fig. 27, 28), and ix) patches of short black thorns of sternum 3 restricted to small spots on each side of sternal impression (Fig. 29).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD0FFA0FF56FC615B26FB12.taxon	description	Description. FEMALE (Fig. 19): Body length 6 – 7 mm. Head: Head 1.3 – 1.4 × as long as wide (Fig. 21). Distance between posterior margin of lateral ocellus and occipital margin about 1.4 × as long as ocellar diameter. Clypeus rather strongly convex, its anteriormost point slightly projecting over supraclypeal area in lateral view. Punctation of clypeus laterally and apically dense with interspaces hardly exceeding diameter of one puncture and on narrow median zone more scattered with interspaces reaching diameter of two to three punctures. Supraclypeal area basally and laterally densely and medioapically sparsely punctate. Labrum about 1.75 × as long as apically wide (Fig. 21); its apical margin shallowly emarginate over entire width. Mandible three-toothed. Proboscis very long (Fig. 19), slightly surpassing coxa of fore leg when folded; second segment of labial palpus about 5 × as long as first segment and 1.55 – 1.65 × as long as compound eye. Third segment of labial palpus as long as fourth segment or slightly shorter. Anterior side of antennal segments (8) 9 – 11 dark reddish-brown. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially distinctly longer than metanotum, flat, crossed by numerous rather fine longitudinal carinae and bordered by narrow impunctate polished zone around its posterior margin (Fig. 22). Anterior surface of coxa of fore leg medially very sparsely punctate with interspaces reaching the diameter of several punctures (Fig. 23). Apical margin of tibial spur of fore leg largely truncate without or with only barely perceivable tip. Tibial spurs of hind leg yellowish to brownish. Metasoma: Marginal zones of terga 1 – 4 with dense and short white hair bands (Fig. 19), which are usually not interrupted in fresh specimens. Terga 2 – 3 basally not or only weakly constricted. Scopa white, its hairs not plumose (Fig. 19). MALE (Fig. 20): Body length 8 – 8.5 mm. Head: Head 1.1 – 1.15 × long as wide. Distance between posterior margin of lateral ocellus and occipital margin 1.25 – 1.35 × as long as ocellar diameter. Hypostomal carina prolonged into large tooth-like projection of roughly triangular shape in lateral view (Fig. 24). Genal area along lower margin of compound eye distinctly impressed and almost impunctate. Proboscis very long, slightly surpassing coxa of fore leg when folded; second segment of labial palpus about 5 × as long as first segment and about 1.35 × as long as compound eye; third segment of labial palpus as long as fourth segment or slightly shorter. Antennal segments 5 – 12 asymmetrical with lower margin apically prolonged into acute tip and shorter than wide to as long as wide (fig. 25). Last antennal segment roundish and distinctly button-like (Fig. 25). Anterior side and to different degree also posterior side of antennal segments 5 – 12 yellowish to yellowish-white (Fig. 25); antennal segments 1 – 4 and 13 completely black (Fig. 25). Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially distinctly longer than metanotum, flat, crossed by numerous rather fine longitudinal carinae and bordered by narrow impunctate polished zone around its posterior margin. Mesosternum medioapically with narrow and almost parallel-sided impression, the margins of which are distinctly raised. Anterior surface of coxa of fore leg almost impunctate. Apical margin of tibial spur of fore leg truncate. Metasoma: Marginal zones of terga 1 – 5 (6) with loose white hair bands (Fig. 20), which are widely interrupted on terga 1 – 3 (4). Terga 2 – 3 basally not or only weakly constricted. Tergum 7 basally with oval pit, laterally triangularly toothed and apically with two teeth, which are roughly parallel-sided, slightly longer than basally wide, apically (obliquely) truncate and separated from each other by semicircular incision at least three times as wide as tooth width (Fig. 26). Apical margin of sternum 1 medially with semicircular incision. Median projection of sternum 2 roughly triangular in ventral view, distinctly rising towards posterior margin and composed of two parts: anterior part with projecting lamella, which is short, flat, apically rounded, separated from posterior part by distinct constriction and largely overhanging concave anterior surface of median projection (Fig. 27, 28); posterior part medially with more or less shagreened and parallel-sided impression and laterally with polished margins diverging towards sternal margin (Fig. 28). Sterna 2 – 3 lateroapically with small and well delimited tuft of short white hairs. Sternum 3 with two small spots of short black thorns on each side of apical sternal impression, which is anteriorly bordered by arched transversal swelling (Fig. 29). Sternum 3 with row of stiff yellowish bristles along its apical margin (Fig. 29). Sternum 4 densely covered with whitish pilosity, its apical margin with membraneous appendage that is medially divided into two upwardly curved lobes. Apical margin of sternum 5 with single row of long, yellowish and moniliform bristles (Fig. 29). Sternum 6 roughly quadrangular in shape, its apical half polished, very sparsely haired and impunctate.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD0FFA0FF56FC615B26FB12.taxon	distribution	Distribution. Southern central to eastern Turkey, northern Iraq (Fig. 74). Pollen hosts. Unknown. Nesting biology. Unknown, but presumably oligolectic on Lamiaceae by analogy to C. meronense.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD0FFA0FF56FC615B26FB12.taxon	etymology	Etymology. The species epithet refers to the long and narrow head of the female (gr. “ dolichos ” = long, lat. “ cephalus ” = head).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD2FFA6FF56FB3D5B43F99E.taxon	materials_examined	Holotype. ISRAEL: Northern District: Mount Meron, Station, 4.5.2000, ♂ (leg. M. Török). Deposited in the Entomological Collection of ETH Zurich. Paratypes. ISRAEL: Northern District: Yir’on, 14.5.1974, 1 ♂ (leg. A. Freidberg); 40 km NE Haifa, 1 km E Hurfeish, 33 ° 01 ′ N / 35 ° 21 ′ E, 15.5.1996, 7 ♀ (leg. C. Schmid-Egger); Har Meron, 33 ° 0 ′ N / 35 ° 25 ′ E, 1120 m, 26.5.2009, 1 ♂ (leg. A. Freidberg); 1 km SW Ziv › on, 33.019 ° N 35.407 ° E, 15.5.2015, 1 ♀, 1 ♂ (leg. G. Pisanty); 1 km SW Ziv › on, 33.02 ° N 35.41 ° E, 22.4.2016, 3 ♀ (leg. G. Pisanty); 1 km SW Ziv’on, 33.0195 ° N / 35.408 ° E, 21.4.2017, 1 ♂ (leg. G. Pisanty). Deposited in the Entomological Collection of ETH Zurich and the Steinhardt Museum of Natural History Tel Aviv.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD2FFA6FF56FB3D5B43F99E.taxon	diagnosis	Diagnosis. The females of C. meronense can be separated from those of the two other species of the C. meronense group by the following combination of characters: i) head 1.1 – 1.2 × as long as wide (Fig. 32), ii) third segment of labial palpus shorter than fourth segment, iii) basal area of propodeum medially about as long as metanotum (Fig. 33), and iv) anterior surface of coxa of fore leg densely punctate with interspaces rarely exceeding the diameter of one puncture (Fig. 34). The males differ from the two related species by the following combination of characters: i) hypostomal area with tooth-like projection of roughly rectangular shape (Fig. 36), ii) third segment of labial palpus shorter than fourth segment, iii) antennal segments 5 - 12 symmetrical and longer than wide (Fig. 35), iv) last antennal segment elongated oval and not distinctly button-like (Fig. 35), v) anterior side of antennal flagellum predominantly yellowish-red (Fig. 25), vi) basal area of propodeum medially about as long as metanotum, vii) anterior margin of median projection of sternum 2 evenly rounded (Fig. 39), and viii) patches of short black thorns of sternum 3 narrow and curved, covering entire sides of sternal impression (Fig. 39).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD2FFA6FF56FB3D5B43F99E.taxon	description	Description. FEMALE (Fig. 30): Body length 6.5 – 7.5 mm. Head: Head 1.1 – 1.2 × as long as wide (Fig. 32). Distance between posterior margin of lateral ocellus and occipital margin 1.4 - 1.6 × as long as ocellar diameter. Clypeus rather strongly convex, its anteriormost point slightly projecting over supraclypeal area in lateral view. Punctation of clypeus laterally and apically very dense with interspaces rarely exceeding diameter of half a puncture and on narrow median zone more scattered with interspaces reaching diameter of one to two punctures. Supraclypeal area basally and laterally densely and medioapically more sparsely punctate. Labrum 1.8 – 1.9 × as long as apically wide; its apical margin shallowly emarginate over entire width. Mandible three-toothed. Proboscis very long (Fig. 30), slightly surpassing coxa of fore leg when folded; second segment of labial palpus about 4.75 × as long as first segment and 1.3 – 1.4 × as long as compound eye. Third segment of labial palpus shorter than fourth segment. Anterior side of antennal segments (8,9) 10 – 11 reddish-brown. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially about as long as metanotum, flat, crossed by numerous rather fine longitudinal and occasionally branched carinae and bordered by narrow impunctate polished zone around its posterior margin (Fig. 33). Anterior surface of coxa of fore leg densely punctate with interspaces rarely exceeding the diameter of one puncture (Fig. 34). Apical margin of tibial spur of fore leg prolonged into very short tip. Tibial spurs of hind leg yellowish-brown. Metasoma: Marginal zones of terga 1 – 4 with dense and short white hair bands (Fig. 30), which are usually not interrupted in fresh specimens. Terga 2 – 3 basally not or only weakly constricted. Scopa white, its hairs not plumose (Fig. 30). MALE: Body length 7.5 – 8.5 mm. Head: Head 1.05 – 1.1 × long as wide. Distance between posterior margin of lateral ocellus and occipital margin 1.4 – 1.5 × as long as ocellar diameter. Hypostomal carina prolonged into large tooth-like projection of roughly rectangular shape in lateral view (Fig. 36). Genal area along lower margin of compound eye not distinctly impressed and densely punctate. Proboscis very long (Fig. 31), slightly surpassing coxa of fore leg when folded; second segment of labial palpus about 4.5 × as long as first segment and 1.3 - 1.4 as long as compound eye; third segment of labial palpus shorter than fourth segment. Antennal segments 5 – 12 almost symmetrical and longer than wide (Fig. 35). Last antennal segment elongated oval and not distinctly button-like (Fig. 35). Anterior side and to different degree also posterior side of antennal segments 4 – 12 yellowish-red (Fig. 35); antennal segments 1 – 3 and 13 (almost) completely black (Fig. 35). Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum about as long as metanotum, flat, crossed by numerous rather fine longitudinal and occasionally branched carinae and bordered by narrow impunctate polished zone around its posterior margin. Mesosternum medioapically with widely triangular and densely sculptured impression, the margins of which are only basally slightly raised. Anterior surface of coxa of fore leg rather densely punctate with interspaces reaching the diameter of one, rarely one and a half to two punctures. Apical margin of tibial spur of fore leg slightly emarginate. Metasoma: Marginal zones of terga 1 – 5 (6) with loose white hair bands (Fig. 31), which are widely interrupted on terga 1 – 3 (4). Terga 2 – 3 basally not or only weakly constricted. Tergum 7 basally with oval pit, laterally triangularly toothed and apically with two teeth, which are roughly parallel-sided, about as long as to slightly longer than basally wide, apically (obliquely) truncate and separated from each other by semicircular incision about twice as wide as tooth width (Fig. 37). Apical margin of sternum 1 medially distinctly emarginate. Median projection of sternum 2 half-elliptical and concave in ventral view, its anterior half evenly rounded in ventral view and overhanging concave anterior surface of median projection in lateral view (Fig. 38, 39). Sterna 2 – 3 lateroapically with tuft of long white hairs. Sternum 3 with two narrow and curved spots of short black thorns, which cover entire sides of sternal impression (Fig. 39). Sternum 3 with row of stiff yellowish bristles along its apical margin (Fig. 39). Sternum 4 densely covered with whitish pilosity, its apical margin with membraneous appendage that is medially divided into two flat lobes. Apical margin of sternum 5 with single row of long, yellowish and moniliform bristles (Fig. 39) Sternum 6 roughly quadrangular in shape, its apical half polished, very sparsely haired, impunctate and medially impressed.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD2FFA6FF56FB3D5B43F99E.taxon	distribution	Distribution. Northern Israel (Fig. 74). Pollen hosts. Seven pollen loads from three different localities in northern Israel exclusively consisted of hexacolpate pollen of the Nepetoideae (Lamiaceae), strongly suggesting that C. meronense is oligolectic on Lamiaceae. This assumption is supported by the observation of a male visiting the flowers of Salvia (label record). Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD2FFA6FF56FB3D5B43F99E.taxon	etymology	Etymology. The species epithet refers to the Har Meron, a mountain in northern Israel, where the new species was found.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD4FFA4FF56F9B159B0F8B7.taxon	materials_examined	Holotype. TURKEY: Adana: Pozantı, 10.5. – 15.5.1955, 1 ♂ (leg. Seidenstücker). Deposited in the Entomological Collection of ETH Zurich. Paratypes. IRAQ: Dahuk: Mount Gara, 1912 m, 37.015833 ° N / 43.350556 ° E, 11.5.2023, 6 ♂ (leg. D. Baiocchi), Mount Gara, 5 km E Ashewa 1750 – 1950 m, 37.0158 ° N / 43.3505 ° E, 30.5. – 12.6.2024, 1 ♀ (leg. D. Baiocchi). Deposited in the Entomological Collection of ETH Zurich.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD4FFA4FF56F9B159B0F8B7.taxon	diagnosis	Diagnosis. The females of C. miripalpum can be separated from those of the other two species of the C. meronense group by the following combination of characters: i) head about 1.4 as long as wide, ii) proboscis reaching coxa of middle leg in repose, iii) second segment of labial palpus slightly more than 2 as long as compound eye, iv) third segment of labial palpus about 2.5 × as long as fourth segment (Fig. 42), v) labrum about 2 × as long as apically wide, v) basal area of propodeum medially slightly longer than metanotum (Fig. 43), and vi) anterior surface of coxa of fore leg medially sparsely punctate with interspaces reaching the diameter of several punctures. The males differ from the related species by the following combination of characters: i) hypostomal area without tooth-like projection, ii) third segment of labial palpus about 2.5 × as long as fourth segment, iii) antennal segments 8 – 12 symmetrical and longer than wide (Fig. 44), iv) last antennal segment cylindrical (Fig. 44), v) antenna entirely dark brown to black (Fig. 44), vi) basal area of propodeum medially slightly longer than metanotum, vii) anterior margin of median projection of sternum 2 evenly rounded (Fig. 47), and viii) patches of short black thorns of sternum 3 restricted to rather small spots on each side of sternal impression (Fig. 48).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD4FFA4FF56F9B159B0F8B7.taxon	description	Description. FEMALE (Fig. 40): Body length 7.5 mm. Head: Head about 1.4 × as long as wide. Distance between posterior margin of lateral ocellus and occipital margin about 1.5 × as long as ocellar diameter. Clypeus rather strongly convex, its anteriormost point slightly projecting over supraclypeal area in lateral view. Punctation of clypeus laterally and apically dense with interspaces hardly exceeding diameter of one puncture and on narrow median zone more scattered with interspaces reaching diameter of two punctures. Supraclypeal area basally and laterally densely and medioapically sparsely punctate. Labrum about 2 × as long as apically wide; its apical margin shallowly emarginate over entire width. Mandible three-toothed. Proboscis very long (Fig. 40), reaching coxa of middle leg when folded; second segment of labial palpus about 5.5 × as long as first segment and about 2.1 × as long as compound eye. Third segment of labial palpus about 2.5 × as long as fourth segment (Fig. 42). Antenna uniformly dark brown to black. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially slightly longer than metanotum, flat, crossed by numerous rather fine longitudinal carinae and bordered by narrow impunctate polished zone around its posterior margin (Fig. 43). Anterior surface of coxa of fore leg medially very sparsely punctate with interspaces reaching the diameter of several punctures. Apical margin of tibial spur of fore leg prolonged into very short tip. Tibial spurs of hind leg brownish. Metasoma: Marginal zones of terga 1 – 4 with dense and short white hair bands (Fig. 40), which are usually not interrupted in fresh specimens. Terga 2 – 3 basally not or only weakly constricted. Scopa white, its hairs not plumose (Fig. 40). MALE (Fig. 41): Body length 8 – 8.5 mm. Head: Head about 1.1 × as long as wide. Distance between posterior margin of lateral ocellus and occipital margin 1.4 – 1.5 × as long as ocellar diameter. Hypostomal area without tubercles or tooth-like projections and genal area along lower margin of compound eye not impressed and densely punctate. Proboscis very long (Fig. 41), reaching coxa of middle leg when folded; second segment of labial palpus 5 – 5.5 × as long as first segment and 1.7 - 1.85 × as long as compound eye. Third segment of labial palpus about 2.5 × as long as fourth segment. Antennal segments 5 – 12 symmetrical and longer than wide (Fig. 44). Last antennal segment cylindrical (Fig. 44). Antenna uniformly dark brown to black (Fig. 44). Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially slightly longer than metanotum, flat, crossed by numerous rather fine longitudinal carinae and bordered by narrow impunctate polished zone around its posterior margin. Mesosternum medioapically with narrowly triangular impression, the margins of which are only weakly raised. Anterior surface of coxa of fore leg medially sparsely punctate with interspaces reaching the diameter of several punctures. Apical margin of tibial spur of fore leg slightly emarginate. Metasoma: Marginal zones of terga 1 – 5 (6) with loose white hair bands (Fig. 41), which are widely interrupted on terga 1 – 3 (4). Terga 2 – 3 basally not or only weakly constricted. Tergum 7 basally with oval pit, laterally triangularly toothed and apically with two teeth, which are roughly parallel-sided, about as long as to slightly longer than basally wide, apically (obliquely) truncate and separated from each other by a roughly rectangular space two to three times as wide as tooth width (Fig. 45). Ventral base of apical teeth of tergum 7 with large backwardly and inwardly directed tooth-like projection, the tip of which is clearly visible when tergum 7 is viewed from above (Fig. 45). Apical margin of sternum 1 medially distinctly emarginate. Median projection of sternum 2 half-elliptical and concave in ventral view, its anterior half evenly rounded in ventral view and largely overhanging concave anterior surface of median projection in lateral view (Fig. 46, 47). Sterna 2 – 3 lateroapically with tuft of long white hairs. Sternum 3 with two small spots of short black thorns on each side of apical sternal impression, which is anteriorly bordered by arched transversal swelling (Fig. 48). Sternum 3 with row of stiff yellowish bristles along its apical margin (Fig. 48). Sternum 4 densely covered with whitish pilosity, which surpasses apical margin and is apically curled downwards. Apical margin of sternum 5 with single row of long, yellowish and moniliform bristles. Sternum 6 roughly quadrangular in shape, its apical half polished, very sparsely haired, impunctate and medially impressed.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD4FFA4FF56F9B159B0F8B7.taxon	distribution	Distribution. Southern central Turkey, northern Iraq (Fig. 74). Pollen hosts. Unknown, but presumably oligolectic on Lamiaceae by analogy to C. meronense. Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD4FFA4FF56F9B159B0F8B7.taxon	etymology	Etymology. The species epithet refers to the unusually long segment 3 of the labial palpus (lat. “ mirus ” = remarkable, amazing), which is a unique character in C. (Chelostoma).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD7FFABFF56FE31581AFACA.taxon	materials_examined	Holotype. IRAN: Kohgiluyeh and Boyer-Ahmad: Yasuj, Sarb-e Taveh, 2030 ± 600 m, 30.545 ° N / 51.61 ° E, ♂ (leg. M. Kafka). Deposited in the Entomological Collection of ETH Zurich. Paratypes. IRAN: Ilam: Abda Man Dinar Gaouh, 1830 m, 32.915 ° N / 47.301 ° E, 12.5.2016, 2 ♀ (leg. M. Kafka); Kohgiluyeh and Boyer-Ahmad: Yasuj, Sarb-e Taveh, 2030 ± 600 m, 30.545 ° N / 51.61 ° E, 4.5.2016, 3 ♀, 4 ♂ (leg. M. Kafka); Likak, Bach Goland, 1640 m, 30.993 ° N / 50.148 ° E, 7.5.2016, 2 ♀ (leg. M. Kafka); Lorestan: Dorud, Lanjabad, 960 m, 33.419 ° N / 48.986 ° E, 10.5.2016, 1 ♀ (leg. M. Kafka). IRAQ: Dahuk: Mount Gara, 1912 m, 37.015833 ° N / 43.350556 ° E, 11.5.2023, 2 ♂ (leg. D. Baiocchi). TURKEY: Hakkari: 8 km N Oramar (= Dağlıca), 1500 m, 10.6.1981, 1 ♀ (leg. K. Warncke); Tanin-Tanin pass, 2300 m, 19.5.1989, 1 ♂ (leg. K. Warncke). Deposited in the Entomological Collection of ETH Zurich. Additional material. IRAQ: Dahuk: Mount Gara, 1912 m, 37.015833 ° N / 43.350556 ° E, 11.5.2023, 2 ♂ (leg. D. Baiocchi). TURKEY: Hakkari: Halil pass E Süvari, 1900 m, 1.6.1980, 2 ♂ (leg. M. Schwarz); 8 km N Oramar (= Dağlıca), 1500 m, 10.6.1981, 2 ♀, 1 ♂ (leg. K. Warncke); Şemdinli, 1700 m, 12.6.1981, 1 ♀, 2 ♂ (leg. K. Warncke); Siirt: E Şirnak, 4.6.1977, 8 ♀, 2 ♂ (leg. K. Warncke).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD7FFABFF56FE31581AFACA.taxon	diagnosis	Diagnosis. C. kurdistanicum is similar to the other representatives of the C. mocsaryi species group. The females differ from the other species of the C. mocsaryi group by the following combination of characters: i) body length not exceeding 7 mm, ii) clypeus medially flat to slightly concave (Fig. 52), iii) vertex rather short with distance between outer margins of posterior ocelli being distinctly longer than distance between anterior margin of lateral ocellus and occipital margin (Fig. 51), iv) labrum on upper side almost straight over entire length, its punctate apicalmost part medially about 0.5 × as long as apically wide (Fig. 52) and transitioning without ledge into the impunctate more basal part, which is usually completely shagreened and laterally lacks a narrow longitudinal groove along the labral margin (only visible if labrum is fully exposed), and v) inner margin of mandible with distinct triangular tooth between base and second outermost tooth, rendering mandible three-toothed (Fig. 53). The males can be distinguished from the other species of the C. mocsaryi group by the following combination of characters: i) hypostomal area with two small tubercles adjacent to hypostomal carina (Fig. 54), ii) polished impunctate zone of genal area along lower margin of compound eye much narrower than width of antennal flagellum in its apical half, iii) median projection of sternum 2 in ventral view roughly triangular and anteriorly not prolonged into almost vertically projecting lamella, its anterior margin angular but not sharp and not overhanging anterior surface, and angle between anterior and ventral surface about 90 degrees in lateral view (Fig. 57, 58), and iv) patches of short black thorns on sternum 3 small, roundish and separated from each other by a distance at least twice as large as maximum width of a thorn patch (Fig. 58).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD7FFABFF56FE31581AFACA.taxon	description	Description. FEMALE (Fig. 49): Body length 6 – 7 mm. Head: Head 1.05 – 1.1 × as long as wide. Distance between posterior margin of lateral ocellus and occipital margin 1.3 - 1.4 × as long as ocellar diameter and distance between outer margins of posterior ocelli distinctly longer than distance between anterior margin of lateral ocellus and occipital margin (Fig. 51). Clypeus medially flat to slightly concave (Fig. 52), its punctation dense with interspaces only rarely reaching the diameter of one puncture except medially and basally where the interspaces may reach the diameter of one and a half punctures. Apical margin of clypeus medially straight and denticulate and laterally slightly protruding. Labrum 1.5 – 1.7 × as long as apically wide, basally flat, apically truncate to very shallowly emarginate and in lateral view upper side almost straight over entire length; its punctate apicalmost part medially about 0.5 × as long as apically wide and transitioning without ledge into impunctate more basal part (Fig. 52); its impunctate basal part usually completely shagreened, laterally without narrow polished longitudinal groove along labral margin (Fig. 52). Mandible three-toothed, its inner margin with distinct triangular tooth between base and second outermost tooth (Fig. 53). Proboscis short (Fig. 49), not reaching till base of fore coxa when folded; second segment of labial palpus 2.75 – 3.1 × as long as first segment and about 0.5 × as long as compound eye. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially 0.75 - 0.9 × as long as metanotum, impressed over entire width, crossed by rather coarse longitudinal carinae and bordered posteriorly by a raised and polished to imperceivably shagreened transverse ridge. Metasoma: Terga 2 – 3 not or only weakly constricted at base. Marginal zones of terga 1 – 4 with short and dense white hair bands (Fig. 49), which are not interrupted in fresh specimens. Scopa white, its hairs not plumose (Fig. 49). MALE (Fig. 50): Body length 6.5 – 8 mm. Head: Head about as long as wide. Genal area along lower margin of compound eye with polished impunctate zone, which is distinctly narrower than width of antennal flagellum in its apical half. Distance between posterior margin of lateral ocellus and occipital margin 1.4 – 1.5 × as long as ocellar diameter. Hypostomal area with two small tubercles adjacent to hypostomal carina (Fig. 54). Proboscis short (Fig. 50), not reaching till base of coxa of fore leg when folded; second segment of labial palpus about 3 × as long as first segment and 0.5 – 0.6 × as long as compound eye. Antennal segments 3 – 13 longer than wide, anterior side and to different degrees also posterior side of segments (4) 5 – 12 (13) yellowish-brown to yellowish-red. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially 0.75 - 1 × as long as metanotum, impressed over entire width, crossed by rather coarse longitudinal carinae and bordered posteriorly by a raised and polished to imperceivably shagreened transverse ridge (Fig. 55). Tibial spur of fore leg apically truncate to almost imperceivably emarginate. Metasoma: Marginal zones of terga 1 – 5 with rather short and dense white hair bands (Fig. 50), which are widely interrupted on terga 1 – 3. Terga 2 – 3 basally not or only weakly constricted. Tergum 7 basally with roundish pit and apically with two teeth, which are narrow and parallel-sided, slightly diverging, about 2 × as long as basally wide, apically weakly rounded and separated from each other by a semicircular incision, which is maximally 2.5 – 3 × as wide as tooth width (Fig. 56). Ventral base of apical teeth of tergum 7 with large backwardly and inwardly directed tooth-like projection, the tip of which is clearly visible when tergum 7 is viewed from above (Fig. 56). Apical margin of sternum 1 medially shallowly emarginate. Median projection of sternum 2 in ventral view roughly triangular in shape with anteriorly rounded tip, medially slightly impressed and densely punctate and laterally surrounded by narrow impunctate and polished zone (Fig. 58); in lateral view, anterior margin of median projection angular but neither prolonged nor overhanging anterior surface of median projection, and angle between anterior and ventral surface almost 90 degrees (Fig. 57). Sternum 3 with well-developed and long whitish pilosity and medioapically with two small roundish patches of short black thorns, which are separated from each other by a distance of at least twice as large as the maximum width of a thorn patch (Fig. 58); apical margin of sternum 3 medially slightly emarginate and with short membraneous appendage that is medially divided into two lobes. Sternum 4 densely covered with whitish pilosity, which surpasses apical margin and is apically curled downwards. Apical margin of sternum 5 with a single row of long and thin yellowish-white bristles. Sternum 6 roughly quadrangular in shape, its apical half polished, almost hairless, very sparsely punctate and medially impressed.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD7FFABFF56FE31581AFACA.taxon	distribution	Distribution. Southeastern Turkey, northern Iraq, western Iran (Fig. 74). Pollen hosts. Three pollen loads from two different localities exclusively consisted of an identical type of monocotyledonous pollen that could not be distinguished from pollen of Ornithogalum (Asparagaceae) at a magnification of 400 ×, suggesting that C. kurdistanicum is oligolectic on Ornithogalum as is the closely related species C. mocsaryi (see below). This assumption is supported by the fact that C. kurdistanicum was collected near Yasuj in eastern Iran together with C. mocsaryi at the very same place and date, which makes it probable that Ornithogalum served as pollen host for both species. Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD7FFABFF56FE31581AFACA.taxon	etymology	Etymology. The species epithet refers to the distribution area, which includes large parts of Kurdistan, the historical settlement area of the Kurds.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD9FFA8FF56FA0558A9F9E2.taxon	description	New records. ARMENIA: Ararat: Khosrov State Reserve, 10.6.2017, 1 ♀ (leg. M Kasparek); Wajoz Dsor: Shatin, 1339 m, 16.5.2023, 1 ♂ (leg. V. Leclercq). BULGARIA: Burgas: Slanchev brjag, 42.7209 ° N / 27.7302 ° E, 1.7.2017, 1 ♀ (leg. T. Kwast); Chaskowo: Dervinska Mogila, 25 km NE Svilengrad, 500 m, 20.6.2008, 1 ♀ (leg. M. Halada); Plovdiv: Rodopi, Hrabrino, 20.5.1997, 1 ♀, 1 ♂ (leg. Zaykov); Varna: Varna, 6.1963, 1 ♂ (leg. Sekera). CROATIA: Primorje-Gorski kotar: Opatja, 5.6. – 19.6.1976, 1 ♂ (leg. P. Witzgall). CYPRUS: Nicosia: Kykko, 34 ° 58 ′ N / 22 ° 44 ′ E, 800 m, 11.5.2014, 1 ♀ (leg. M. Kafka). FRANCE: Var: Gonfaron, Les Ribasses, 43 ° 20 ′ 13 ′′ N / 6 ° 17 ′ 49.3 ′′ E, 140 m, 11.5.2003, 1 ♀ (leg. Vansthertem). GEORGIA: Kvemo Kartli: Ghevi, 30 km W Tbilisi, 13.6.2015, 1 ♂ (leg. M. Snizek). GREECE: Aegean Islands: Chios, Agios Georgios Sikousis, 38.308 ° N / 26.0383 ° E, 26.4.2012, 1 ♂ (leg. M. Taylor); Lesvos, 2 km W Vatousa, 200 m, 19.4.2001, 5 ♀ (S. Roberts); Rhodes, Lindos, 10.4.1970, 1 ♂ (leg. A. C. Ellis); Attica: Athen, Mt. Parnes, 600 m, 17.4.1977, 6 ♂ (leg. K. Guichard); Central Greece: Delphi, 5.9.2005, 1 ♀ (leg. J. Halada); Central Macedonia: Epanomi, 4.4.1959, 2 ♀, 1 ♂ (leg. Rathmayer); Crete: Nea Kria Vrisi, 35 ° 08 ′ 7 ′′ N / 24 ° 37 ′ 9 ′′ E, 15.4.2016, 1 ♂ (leg. J. Smit); Epirus: 40 km S Igoumenitsa, 16.5.2005, 1 ♀ (leg. J. Halada); Peloponnese: Mani, Agios Dimitrios, 29.4.2001, 2 ♀, 1 ♂ (leg. A. Müller); Thessaly: Meteora, 23.5.1991, 1 ♀ (leg. Zinnert); Western Greece: Kalogria (Achaia), 10.4.1996, 1 ♂ (leg. W. Arens). IRAN: Kohgiluyeh and Boyer-Ahmad: Yasui, Sarb-e Taveh, 30.545 ° N / 51.61 ° E, 2030 ± 600 m, 4.5.2016, 3 ♀ (leg. M. Kafka). IRAQ: Dahuk: Kaneka, NW Scren, 829 m, 37.05277 ° N / 43.26332 ° E, 9.5.2023, 1 ♂ (leg. D. Baiocchi). ISRAEL AND PALESTINE: Central District: Judean foothills, Ya’ar Adolam, 20.4.2011, 1 ♀ (leg. T. Koznichki); Haifa District: Mount Carmel, En Hod, 80 m, 2.4.2000, 1 ♂ (leg. S. Roberts); Northern District: Dovev, 3.4.2016, 1 ♂ (leg. O. Winberger); Southern District: 3 km NW Bet Nir, 31.667 ° N / 34.845 ° E, 5.4.2015, 1 ♂ (leg. G. Pisanty). ITALY: Puglia: Monte Gargano, M. S. Angelo, 750 m, 25.5.1993, 1 ♂ (leg. A. Müller); Toscana: Rocca d’Orcia, 24.5.2001, 1 ♀ (leg. K. Hirt); Veneto: Brussa, 17.5.1899, 1 ♀ (leg. A. Weis). JORDAN: Jerash: 10 km N Jerash, 23.04.07, 1 ♀, 1 ♂ (leg. C. Praz, C. Sedivy, A. Müller). ROMANIA: Cluj: Visea NE Cluj-Napoca, 46 ° 51 ′ 04 ′′ N / 23 ° 52 ′ 14 ′′ E, 19.6.2022, 2 ♂ (leg. J. Schwarz). SERBIA: Belgrad e: Drazevac N Belgrade, 27. – 28.6.1981, 1 ♀ (leg. Day, Fitton). SLOVENIA: Obalno-kraška: Portoroz, 26.5. – 23.6.1974, 2 ♂ (leg. F. Parré). TURKEY: Aksaray: Ihlara valley, 38 ° 15 ′ N / 36 ° 18 ′ E, 13.6.2008, 1 ♀ (leg. M. Kafka); Bingöl: Buğlan Geçidi, 40 km NW Muş, 38 ° 56 ′ N / 41 ° 09 ′ E, 1600 m, 27.5.2010, 1 ♀ (leg. Z. Pedr); Bolu: Abant Gölü, 4.6.2000, 1 ♂ (leg. K. Denes); Gaziantep: 13 km N Islahiye Fevzipaşa, 10.5.2002, 3 ♀, 1 ♂ (leg. F. Kantner); Konya: Bozkir, dry forest near Üçpınar, 1200 m, 4.6.1993, 1 ♀, 2 ♂ (leg. S. Risch); Muğla: Kuyucak, 11.5.2010, 1 ♀ (leg. M. Kasparek); Siirt: E Şirnak, 4.6.1977, 1 ♀ (leg. K. Warncke).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD9FFA8FF56FA0558A9F9E2.taxon	distribution	Distribution. Southern Europe (France, Italy including Sicily, Slovenia, Croatia, Serbia, Greece including Aegean Islands and Crete, Bulgaria, Romania, Ukraine including Crimea), Turkey, Cyprus, Caucasus (Armenia, Georgia, Azerbaijan), northern Iraq, western Iran and Levant (Lebanon, Jordan, Israel and Palestine). The species seems to be absent from the Iberian Peninsula. Pollen hosts. Oligolectic on Ornithogalum (Asparagaceae), e. g. O. narbonense, O. pyramidale, O. pyrenaicum (Gogala 1999, 2014; Sedivy et al. 2008; Westrich 2010). Nesting biology. C. mocsaryi nests in insect burrows in dead wood and in hollow stems (Banaszak & Romasenko 2001; Westrich 2010; Gogala 2014).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFD9FFA8FF56FA0558A9F9E2.taxon	description	Note. C. dolosum sensu Ungricht et al. (2008) was formerly regarded as a species different from C. mocsaryi and is identical with the taxon newly named as C. kurdistanicum sp. nov. in the present publication (see above). The examination of the female lectotype of C. dolosum (Benoist, 1935) revealed that the type is a small individual of C. mocsaryi. In addition, a conspecifity of C. dolosum and C. kurdistanicum can be excluded because the type locality of C. dolosum in northwestern Turkey is far away from the known distribution range of C. kurdistanicum, which extends from southeasternmost Turkey to eastern Iran.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDAFFAEFF56F96D5EF1FA82.taxon	materials_examined	Holotype. ISRAEL AND PALESTINE: Southern District: Lakhish, 20.3.2013, ♂ (leg. T. Shapira). Deposited in the Steinhardt Museum of Natural History Tel Aviv. Paratypes. ISRAEL AND PALESTINE: Southern District: Har Horesha, 30 ° 36 ′ N / 34 ° 31 ′ E, 6.4.2005, 1 ♂ (leg. L. Friedmann). Deposited in the Entomological Collection of ETH Zurich.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDAFFAEFF56F96D5EF1FA82.taxon	diagnosis	Diagnosis. C. negevense is similar to the other representatives of the C. mocsaryi species group. While the females are not yet known, the males differ from the other species of the C. mocsaryi group by the following combination of characters: i) hypostomal area with two tooth-like projections adjacent to hypostomal carina (Fig. 60), ii) polished impunctate zone of genal area along lower margin of compound eye narrower than width of antennal flagellum in its apical half (Fig. 61), iii) upper teeth of tergum 7 basally slightly constricted, medially weakly widened and apically slightly curved, largely hiding lower teeth when seen from above (Fig. 62), iv) median projection of sternum 2 in ventral view half-elliptical and anteriorly not prolonged into almost vertically projecting lamella, its anterior margin sharp and slightly overhanging anterior surface, and angle between anterior and ventral surface much less than 90 degrees in lateral view (Fig. 63, 64), v) patches of black thorns on sternum 3 small, roundish and separated from each other by distance several times larger than maximum width of thorn patch (Fig. 64), and vi) apical part of gonoforceps laterally distinctly flattened, its apex almost linear when seen from behind (Fig. 65).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDAFFAEFF56F96D5EF1FA82.taxon	description	Description. FEMALE: Unknown. MALE (Fig. 59): Body length 8.5 – 9.5 mm. Head: Head 0.95 – 1 × as long as wide. Genal area along lower margin of compound eye with slightly impressed and more or less polished impunctate zone, which is narrower than width of antennal flagellum in its apical half (Fig. 61). Distance between posterior margin of lateral ocellus and occipital margin 1.5 – 1.6 × as long as ocellar diameter. Hypostomal area with two tooth-like projections arising laterally to hypostomal carina (Fig. 60). Proboscis short, not reaching till base of coxa of fore leg when folded. Antennal segments 3 (4) and 13 longer than wide, segments (4) 5 – 12 about as long as wide, anterior side and to large extent also posterior side of segments (3) 4 – 13 yellowish-red. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially 0.6 – 0.7 × as long as metanotum, impressed over entire width, crossed by rather coarse longitudinal carinae and bordered posteriorly by a raised and polished to imperceivably shagreened transverse ridge. Tibial spur of fore leg apically truncate to almost imperceivably emarginate. Metasoma: Marginal zones of terga 1 – 5 with rather short and dense white hair bands (Fig. 59), which are widely interrupted on terga 1 – 3. Tergum 7 basally with roundish pit and apically with two teeth, which are basally slightly constricted, medially weakly widened, apically tapering, 1 – 1.75 × as long as basally wide and separated from each other by a semicircular incision, which is maximally 1.5 – 2 × as wide as maximum tooth width (Fig. 62). Ventral base of apical teeth of tergum 7 with large backwardly directed tooth-like projection, the tip of which is largely hidden by upper tooth when viewed from above (Fig. 62). Apical margin of sternum 1 medially shallowly emarginate. Median projection of sternum 2 in ventral view half-elliptical in shape with rounded anterior margin, medially slightly impressed, sparsely punctate and weakly shagreened and laterally surrounded by largely impunctate and polished to weakly shagreened zone (Fig. 64); in lateral view, anterior margin of median projection sharp and slightly overhanging anterior surface, and angle between anterior and ventral surface much less than 90 degrees (Fig. 63). Sternum 3 with well-developed and long whitish pilosity and medioapically with two small and roundish patches of short black thorns, which are separated from each other by a distance several times larger than the maximum width of the thorn patch (Fig. 64); apical margin of sternum 3 medially slightly emarginate and with short membraneous appendage that is medially divided into two lobes. Sternum 4 densely covered with whitish pilosity, which surpasses apical margin and is apically curled downwards. Apical margin of sternum 5 with a single row of long and thin yellowish-white bristles. Sternum 6 roughly quadrangular in shape, its apical half polished, almost hairless, largely impunctate and medially impressed. Apical part of gonoforceps laterally distinctly flattened, its apex almost linear when seen from behind (Fig. 65).	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDAFFAEFF56F96D5EF1FA82.taxon	distribution	Distribution: Central to southern Israel (Fig. 74). Pollen hosts. Due to the very close (morphological) relationship with C. kurdistanicum and C. ornithogali, which are probably specialized on flowers of Ornithogalum (Asparagaceae) as is C. mocsaryi from the same species group, C. negevense is expected to also restrict pollen collection to this plant genus. In fact, three Ornithogalum species are known to occur in the southernmost Negev near the Egyptian border (Danin & Fragman-Sapir 2016), where the paratype male has been collected. Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDAFFAEFF56F96D5EF1FA82.taxon	etymology	Etymology. The species epithet refers to the occurrence in the Negev in southern Israel.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDCFFACFF56FA4D5E8FF90E.taxon	materials_examined	Holotype. TURKEY: Konya: Bozkır, dry forest near Üçpınar, 1200 m, 4.6.1993, ♀ (leg. S. Risch). Deposited in the Entomological Collection of ETH Zurich. Paratypes. TURKEY: Adana: Pozantı, 10. – 15.5.1955, 1 ♀ (leg. Seidenstücker); Antalya: Taurus Mountains, near Suleymaniye, 1200 m, 25.5.1990, 1 ♀ (leg. S. Risch); Hakkari: 25 km SW Hakkari, 1200 m, 31.5.1980, 1 ♀ (leg. K. Warncke); 5 km N Oramar (= Dağlıca), 11.6.1981, 1 ♀ (leg. M. Kraus); Konya: Taurus Mountains, W Seydişehir, 1200 m, 25.5.1990, 1 ♂ (leg. S. Risch); Mersin: Taurus, Abanoz (Rte Anamur to Kazancı), 1100 – 1200 m,?, 1 ♂ (leg. H. Teunissen). Deposited in the Entomological Collection of ETH Zurich.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDCFFACFF56FA4D5E8FF90E.taxon	diagnosis	Diagnosis. C. ornithogali is similar to the other representatives of the C. mocsaryi species group. The females differ from the other species of the C. mocsaryi group by the following combination of characters: i) vertex rather long with distance between outer margins of posterior ocelli being about as long as distance between anterior margin of lateral ocellus and occipital margin (Fig. 68), and ii) inner margin of mandible without tooth between base and second outermost tooth, rendering mandible two-toothed (Fig. 69). The males of C. ornithogali can be distinguished from the other species of the C. mocsaryi group by the following combination of characters: i) hypostomal area with two tooth-like projections adjacent to hypostomal carina (Fig. 70), ii) polished impunctate zone of genal area along lower margin of compound eye much narrower than width of antennal flagellum in its apical half, iii) upper teeth of tergum 7 narrow and parallel-sided, not hiding lower teeth when seen from above (Fig. 71), iv) median projection of sternum 2 rather wide and anteriorly not prolonged into almost vertically projecting lamella, its anterior margin sharp and slightly overhanging anterior surface, and angle between anterior and ventral surface much less than 90 degrees in lateral view (Fig. 72, 73), v) patches of black thorns on sternum 3 rectangular and separated from each other by a distance shorter than to maximally as long as maximum width of the thorn patch (Fig. 73), and vi) apical part of gonoforceps laterally not flattened, its apex roof-shaped when seen from behind.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDCFFACFF56FA4D5E8FF90E.taxon	description	Description. FEMALE (Fig. 66): Body length 8 – 9 mm. Head: Head 1.05 – 1.1 × as long as wide. Distance between posterior margin of lateral ocellus and occipital margin 2.1 – 2.3 × as long as ocellar diameter and distance between outer margins of posterior ocelli about as long as distance between anterior margin of lateral ocellus and occipital margin (Fig. 68). Clypeus slightly convex with median and apical half diverging by about 150 degrees in lateral view; its punctation very dense with interspaces not exceeding the diameter of half a puncture except medially where the interspaces may rarely reach the diameter of one puncture. Apical margin of clypeus medially straight and denticulate and laterally slightly protruding. Labrum about 2.75 × as long as apically wide, basally flat and apically truncate to very shallowly emarginate. Mandible two-toothed, its inner margin without tooth between base and second outermost tooth (Fig. 69). Proboscis short (Fig. 66), not reaching till base of fore coxa when folded; second segment of labial palpus 2.6 – 2.8 × as long as first segment and about 0.5 × as long as compound eye. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially about as long as to slightly shorter than metanotum, more or less strongly impressed over entire width, crossed by rather coarse longitudinal carinae and bordered posteriorly by a raised and polished transverse ridge. Metasoma: Terga 2 – 3 not or only weakly constricted at base. Marginal zones of terga 1 – 4 with short and dense white hair bands (Fig. 66), which are not interrupted in fresh specimens. Scopa white, its hairs not plumose (Fig. 66). MALE (Fig. 67): Body length 7 – 8 mm. Head: Head about as long as wide. Genal area along lower margin of compound eye with polished to slightly shagreened impunctate zone, which is much narrower than width of antennal flagellum in its apical half. Distance between posterior margin of lateral ocellus and occipital margin 1.4 – 1.5 × as long as ocellar diameter. Hypostomal area with two tooth-like projections arising laterally to hypostomal carina (Fig. 70). Proboscis short (Fig. 67), not reaching till base of coxa of fore leg when folded; second segment of labial palpus about 3 × as long as first segment and about 0.5 × as long as compound eye. Antennal segments 3 and 13 distinctly longer than wide, segments 4 – 12 about as long as wide to slightly longer or shorter; anterior side and to large extent also posterior side of segments (4) 5 – 12 (13) yellowish-red. Mesosoma: Posterior and lateral surface of propodeum largely polished. Basal area of propodeum medially as long as to slightly shorter than metanotum, impressed over entire width, crossed by rather coarse longitudinal carinae and bordered posteriorly by a raised and polished ridge. Tibial spur of fore leg apically truncate to almost imperceivably emarginate. Metasoma: Marginal zones of terga 1 – 5 with rather short and dense white hair bands (Fig. 67), which are widely interrupted on terga 1 – 3. Terga 2 – 3 basally not or only weakly constricted. Tergum 7 basally with roundish pit and apically with two teeth, which are narrow, parallel-sided and slightly diverging, apically truncate to weakly rounded, 1.5 - 1.75 × as long as basally wide, and separated from each other by a semicircular incision, which is about 3 × as wide as tooth width (Fig. 71). Ventral base of apical teeth of tergum 7 with large backwardly and inwardly directed tooth-like projection, the tip of which is visible when viewed from above (Fig. 71). Apical margin of sternum 1 medially very shallowly emarginate. Median projection of sternum 2 in ventral view broadly triangular to half-elliptical in shape with rounded anterior margin, medially slightly impressed, more or less densely punctate and largely polished and laterally surrounded by narrow impunctate and polished to weakly shagreened zone (Fig. 73); in lateral view, anterior margin of median projection sharp and slightly overhanging anterior surface, and angle between anterior and ventral surface much less than 90 degrees (Fig. 72). Sternum 3 with well-developed and long whitish pilosity and medioapically with two rather large and rectangular patches of short black thorns, which are separated from each other by a distance shorter than to maximally as long as maximum width of the thorn patch (Fig. 73); apical margin of sternum 3 medially slightly emarginate and with short membraneous appendage that is medially divided into two lobes. Sternum 4 densely covered with whitish pilosity, which surpasses apical margin and is apically curled downwards. Apical margin of sternum 5 with a single row of long and thin yellowish-white bristles. Sternum 6 roughly quadrangular in shape, its apical half polished, almost hairless, sparsely punctate and medially impressed. Apical part of gonoforceps laterally not flattened, its apex roof-shaped when seen from behind.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDCFFACFF56FA4D5E8FF90E.taxon	distribution	Distribution. Southern central to easternmost Turkey (Fig. 74). Pollen hosts. Four pollen loads from four different localities exclusively consisted of an identical type of monocotyledonous pollen that could not be distinguished from pollen of Ornithogalum (Asparagaceae) at a magnification of 400 ×, suggesting that C. ornithogali is oligolectic on Ornithogalum. Nesting biology. Unknown.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
963987EEFFDCFFACFF56FA4D5E8FF90E.taxon	etymology	Etymology. The species epithet refers to the probable pollen specialization on Ornithogalum.	en	Müller, Andreas, Pisanty, Gideon, Dorchin, Achik (2025): Western Palaearctic Chelostoma bees of the subgenus Chelostoma (Megachilidae, Osmiini): biology, taxonomy and key to species. Zootaxa 5717 (3): 329-369, DOI: 10.11646/zootaxa.5717.3.3, URL: https://doi.org/10.11646/zootaxa.5717.3.3
