Heterarthrus vagans ( Fallen , 1808)

Liston, Andrew, Mutanen, Marko & Viitasaari, Matti, 2019, On the taxonomy of Heterarthrus (Hymenoptera, Tenthredinidae), with a review of the West Palaearctic species, Journal of Hymenoptera Research 72, pp. 83-126 : 103-104

Heterarthrus vagans ( Fallen, 1808)

Hylotoma vagans Fallén, 1808: 47. Syntypes ♀♂, possibly in MZLU. Type locality: Vestergöthland [Sweden, Västergötland].

Heterarthrus vagans . Taeger et al. (2010: 373): complete synonymy listed; but note that Phyllotoma kamtchatica is no longer considered to be conspecific.

Material examined.

Austria: Lower Austria: 1♀ (DEI-GISHym31974), no locality, 10.1988, reared Alnus glutinosa , em. August 1989, leg. E. Altenhofer (SDEI) .

Corsica: 1♂ (DEI-GISHym21130), Haut Ascu , 1493m, 13.06.2013, leg. E. Heibo (private collection E. Heibo) .

Cyprus: Paphos District: 1♀ (DEI-GISHym11091), Kidasi, 16.04.2011, leg. Liston (SDEI) . 3♂ (DEI-GISHym11184, 11189, 11095), Kidasi, 17.04.2011, leg. Liston (SDEI).

Estonia: Saaremaa: 1♀ (TUZ109299), Abruka, gravel pit, 26.07.2017, leg. V. Soon (Univ. Tartu, Nat. Hist. Mus.).

Germany: Brandenburg: 2♀, Langer Berg im Grumsiner Forst , 3- 10.8.1994, leg. DEI Projekt (SDEI) . 1♀, Langer Berg im Grumsiner Forst , 26.07- 02.08.1995, leg. DEI Projekt (SDEI) . 1♂, Langer Berg im Grumsiner Forst , 09.08- 16.08.1995, leg. DEI Projekt (SDEI) . 1♀, Langer Berg im Grumsiner Forst , 5- 12.6.1996, leg. DEI Projekt (SDEI) . 1♀ (DEI-GISHym11000), Müncheberg, Gumnitz , 29.05.2010, leg. Liston (SDEI) . 1♀ (DEI-GISHym83893), Müncheberg, Gumnitz , 25.05.2008, leg. Liston (SDEI) . Thuringia: 2♀, Brandesbachtal bei Netzkater , 27.07- 31.05.1996, Malaise trap, leg. A. & M. Taeger (SDEI) . 1♀, Brandesbachtal bei Netzkater , 22.07- 1.08.1996, Malaise trap, leg. A. & M. Taeger (SDEI) .

Italy: Sicily: 1♀ (DEI-GISHym11097), Portella Zilla , ca 9km E Floresta, 18.05.2010, leg. Liston (SDEI) .

Portugal: Guarda : 1♂, Seia 9 km W, 400 m, 40.42638N, 7.80716W, 4.5.2012, leg. Blank, Jacobs, Liston & Taeger (SDEI) [first record from Portugal] .

Sweden: Torne Lappmark : Abisko National Park , tributary Abisko River , 68.357N, 18.762E, larva in Alnus incana kolaensis (Orlova) Á. Löve & D. Löve, 27.08.2018, leg. Liston (SDEI). Abisko National Park, mouth of Abisko River, 68.323N, 18.745E, 5 larvae in Alnus incana kolaensis , 28.08.2018, leg. Liston (SDEI) .

Remarks.

As already noted above, under Character states, the head and abdomen colour of this species is highly variable. In females the abdomen may be almost completely yellow-red, with only tergum 1 and the apical 2-3 terga and sterna more or less dark ( Fig. 32 ). Equally frequent are however females with nearly the entire dorsum of the abdomen dark. According to Lindqvist (1969), the abdomen may sometimes be nearly completely black, with only the basal sterna obscurely paler. We have not, however, ourselves examined such dark females. Male H. vagans are generally darker than females, with the dorsum of abdomen usually completely dark, and frequently the whole abdomen dark. In females, the face is usually extensively pale on the inner orbits and interantennal area as in Fig. 35 , but sometimes completely black ( Fig. 47 ). The pale colour varies from white, to bright yellow. In both sexes, the coxae and femora are usually completely pale, but occasionally the coxae may be nearly completely black except apically, and up to the basal half of the femora is more or less dark. The thorax is usually entirely black, except for the more or less yellow posteroventral edge of the pronotum, but a male from Corsica (DEI-GISHym21130) has entirely yellow tegulae and the downturned lateral edges of terga 2-6 yellow, with the rest of the abdomen black. This specimen is genetically the most distant from central and northern European, and Canadian H. vagans , which have a quite uniform barcode. Only Alnus alnobetula subsp. suaveolens (Req.) Lambinon & Kerguélen occurs at the Corsican collection locality, so that this can be assumed to be the host. Less distant from the other European and Canadian specimens are specimens from Cyprus and Sicily. See also notes under H. fruticicolum , which may only be a dark specimen of H. vagans .

Host plants and biology.

Alnus species, including all the native West European taxa: A. glutinosa (L.) Gaertn., A. incana (L.) Moench., A. cordata (Loisel.) Duby, and A. alnobetula ssp. alnobetula (Ehrh.) K. Koch ( Buhr 1941, Pschorn-Walcher and Altenhofer 2000); also A. orientalis Decne. ( Liston and Jacobs 2012), A. rubra Bong. ( Humble 2010), and A. subcordata C. A. Mey. ( Liston 2011). The cocoon remains in the leaf. Bivoltine; the second generation more abundant ( Altenhofer 2003).

Distribution.

Widespread in Europe, including the British Isles and Iberian Peninsula ( Taeger et al. 2006), from north of the Arctic circle to some of the larger Mediterranean islands; Turkey ( Muche 1983); introduced to western North America (British Columbia and Washington; Humble 2010, Looney et al. 2016). According to Sundukov (2017), H. vagans has a wide distribution through the East Palaearctic, to the Russian Far East. However, records from at least some of these territories might refer to H. kamtchaticus , and voucher specimens therefore require checking.

Figures

Figures 22 - 32. Heterarthrus 22 - 24 hypopygia: 22 H. wuestneii DEI-GISHym 20656 23 H. cuneifrons DEI-GISHym 31984 24 H. fiora sp. nov. DEI-GISHym 31976 25 - 28 valvulae 3 dorsal: 25 H. microcephalus DEI-GISHym 11397 26 H. leucomela DEI-GISHym 83894 27 H. ochropoda DEI-GISHym 83895 28 H. vagans DEI-GISHym 83896 29 H. leucomela ♀ DEI-GISHym 83894 lateral 30, 31 H. ochropoda ♀ DEI-GISHym 83895 lateral, dorsal 32 H. vagans ♀ DEI-GISHym 83897 dorsal. Scale bar: 1 mm.

Figures 33 - 40. Heterarthrus 33, 34 median mesoscutal lobes ♀: 33 H. ochropoda DEI-GISHym 83895 34 H. leucomela DEI-GISHym 31980 35, 36 head frontal ♂: 35 H. vagans DEI-GISHym 11095 36 H. leucomela DEI-GISHym 31981 37, 38 fore wing ♂: 37 H. ochropoda DEI-GISHym 83898 38 H. microcephalus DEI-GISHym 83899 39, 40 H. fiora sp. nov. ♀ holotype: 39 dorsal 40 head frontal. Scale bar: 1 mm.

Figures 41 - 48. Heterarthrus 41 - 46 H. fiora ♀: 41, 42 head dorsal at different viewing angles, holotype 43 DEI-GISHym 83900 lateral 44, 45 DEI-GISHym 83900 sawsheath dorsal, lateral 46 DEI-GISHym 31977 antenna 47, 48 head frontal ♀: 47 H. vagans DEI-GISHym 11091 48 H. kamtchaticus (H. aihinoensis holotype). Scale bar: 1 mm.