Hylaeus (Nesoprosopis) transversalis COCKERELL, 1924

Dathe, Holger H., 2015, Studies on the systematics and taxonomy of the genus Hylaeus F. (10) New descriptions and records of Asian Hylaeus species (Hymenoptera: Anthophila, Colletidae), Beiträge Zur Entomologie = Contributions to Entomology 65 (2), pp. 223-238 : 233-234

Hylaeus (Nesoprosopis) transversalis COCKERELL, 1924

Hylaeus transversalis COCKERELL, 1924a: 275 . 1 ♂. Holotypus ♂ NMNH Washington, Catalog no. 28008. Type locality: Russia, Okeanskaya, Siberia [Vladivostok, Primorskiy Terr.]. – PROSHCHALYKIN & DATHE 2012: 23; PROSHCHALYKIN 2015: 7.

Prosopis transversalis GUSSAKOVSKIJ, 1932: 65 . ♂. Holotypus ♂ NHRM Stockholm. Type locality: Russia, Vladivostok, Sedanka [Primorskiy Terr.]. Synonymised by PROSHCHALYKIN & DATHE 2012: 23. – OSYTSHNJUK & ROMANKOVA 1995: 487; PROSHCHALYKIN 2003b: 4.

Prosopis sericata WARNCKE, 1972: 748 (nomen novum for Prosopis transversalis GUSSAKOVSKIJ, 1932 , nec COCKERELL 1924a). Synonymised by PROSHCHALYKIN & DATHE 2012: 23.

Hylaeus nippon HIRASHIMA, 1977: 29–32 . ♀ ♂. Holotypus ♀, coll. Kyushu University, Fukuoka No. 2062. Type locality: Japan, Tsushima, Sumo. Synonymised by OSYTSHNJUK & ROMANKOVA 1995: 486.

Hylaeus sericatus: QUEST 2009: 133 ; PROSHCHALYKIN & QUEST 2009: 239.

Hylaeus (Nesoprosopis) dathei CHEN & XU, 2012: 63-64 , 68. ♂. Holotypus coll. CAU Beijing. Type locality: South Korea: Jirisan. New synonym.

Discussion: The species is apparently widely distributed, although not mentioned from mainland China by CHEN & XU (2009). H. transversalis is easily recognisable in the male sex by its transversely ribbed basal area of the propodeum, and the structure of sternum 8 of its terminalia, comprising simple, narrow distal lobe with a few very fine bristles only. One of the males mentioned below from Beijing Botanical Garden has a reticulately sculptured propodeum similar to the females. Huanli Xu observed numerous specimens on flowers of Solidago decurrens LOUREIRO and Sorbaria kirilowii (REGEL & TILING) in the Olympic Forest Park in Beijing (personal communication).

H. transversicostatus (STRAND 1913) from Taiwan also belongs to the group, but in this the distal lobe of sternum 8 is clearly longer and has apically a tuft of short bristles; St7 bears some bristles medially, and the genital capsule has elongated and narrowed gonoforcipes.

The subgenus Nesoprosopis is widely distributed in the southern Palaearctic and seems also here to have developed considerable species richness. About 15 names have been given, but with the exception of the five species occurring on the Japanese Islands, the nominal species have not been sufficiently compared with each other. Are they all valid species? This is certainly possible, if one considers the 60 species that document an unusual diversification of the subgenus in the Hawaii Islands ( DALY & MAGNACCA 2003). On the other hand, the colonisation of archipelagos of volcanic origin follows its own rules. In any case, this group requires a comprehensive revision in the south-east Palaearctic.

Distribution: Japan (Hokkaido, Honshu, Shikoku, Kyushu, Tsushima); Russia (Primorskiy Territory, Kuril Islands); South Korea ( CHEN & XU 2012); new to China (Beijing, Henan Province).

New records:

Material examined: 8 ♂, 1 ♀ . – CHINA. Beijing: Fragrant Hills , 16./ 19.05.2011, 1 ♀, 1 ♂ leg. J.S. Ascher, L. Ding, C. Dong ; Huyu Natural Scenic Area , 40.275N 116.146E, 243 m, 19.05.2011, 1 ♂ leg. J.S. Ascher, L. Ding, J.G. Rozen, F. Yuan ; Chaoyang Park, West Gate , 18.06.2011, 3 ♂ leg. J.S. Ascher, C. Dong ; Jiu Feng , 19.05.2011, 1 ♂ leg. J.S. Ascher, L. Ding, J.G. Rozen, F. Yuan ; Beijing Botanical Garden , 39.996N 116.206E, 77 m, 16.05.2011, 1 ♂ leg. J.S. Ascher, L. Ding, Z. Niu, J.G. Rozen ; Olympic Forest Park, 03.07.2015, 10 ♂, 24 ♀ leg. H. Xu. – Henan Province: Mt. Song, Sao djang Zhai , 12.08.2009, 1 ♂ leg. J.S. Ascher, C. Dong.