Eurygnathomyia bicolor ( Zetterstedt, 1838 )

Ozerov, A. L. & Krivosheina, M. G., 2023, To the fauna of Pallopteridae (Diptera) of Russia, Russian Entomological Journal 32 (2), pp. 234-238 : 235

Eurygnathomyia bicolor ( Zetterstedt, 1838)

Figs 1, 2 .

bicolor Zetterstedt, 1837: 50 ( Sciomyza ). Nomen nudum.

bicolor Zetterstedt, 1838: 739 ( Sciomyza ). Type-locality: “Hab. in Lapponia Umensi rarissime; tantum in silva ad Withelmiiia d. 15–20. Jul. inventa. In Norvegia a D Boheman etiam lecta. (Lapponia.)”.

opomyzina Zetterstedt, 1855: 4793 ( Heteromyza ). Type-locality: “ Scania ” [Skåne] ( Sweden).

MATERIAL. Russia: Khabarovsk Krai, Ikchu River (49.11ºN, 139.27ºE), 350 m, 14. VI .2022, N. Vikhrev (2 ♂♂, 1 ♀, ZMUM) .

DESCRIPTION. Male ( Fig. 1 ). Female. Length of body 4.5–5.2 mm. Length of wing 5.2–5.8 mm.

Head in profile slightly higher than long ( Fig. 1 ). Frons reddish-yellow in ground colour, more or less parallel-sided, slightly broader than long when viewed dorsally; covered in anterior half by black setulae. Face, gena and parafacial from yellow to black. Gena covered by black setulae. Genal height approximately equal to vertical diameter of eye. Postcranium yellow, covered by black setulae. Head with following paired setae: 1 ocellar, 2 orbitals (anterior small), 1 inner vertical, 1 outer vertical, and 1 small postocellar. Antenna short ( Fig. 1 ). Scapus and pedicel reddish-yellow; postpedicel brownish, but yellowish basally, rounded in profile, with long and bare arista ( Fig. 1 ). Palpus reddish-yellow, with black apex.

Thorax densely grey dusted. Scutum covered with rare black setulae and with the following paired setae: 2 postpronotals, 2 equal notopleurals, 1+2 supra-alars, 2 postalars, 2+3 dorsocentrals; acrostichal setae in 1–2 rather well-defined rows. Proepisternum bare, without setulae, but with one strong seta near lower margin. Anepisternum bare.Katepisternum with 4–5 strong setae along upper margin and covered with black setulae in lower corner. Scutellum densely grey dusted, with two pairs of setae approximately equal to each other.

Legs yellow. Fore femur with rows of long posterodorsal and posteroventral setae. Fore tibia with 1 dorsal preapical and 1 posterodorsal preapical setae. Mid femur with 4–5 posteroventral setulae apically. Mid tibia with 1 anterodorsal preapical, 1 posterodorsal preapical, 1 anteroventral apical and 1 posteroventral apical setae. Hind femur with 2 anterodorsal thin setae in apical third and several posteroventral setulae in apical quarter. Hind tibia with 1 anterodorsal preapical and 1 posterodorsal preapical setae.

Wing ( Figs 1, 2 ) transparent with 3 dark areas: along r-m and dm-cu crossveins, also at apex; dark area between costal vein and vein R 2+3 can start from the confluence of subcostal vein in costal vein. Veins yellow. Costal vein spinose ( Fig. 2 ).

Abdomen densely grey dusted, covered with black setulae. End of male abdomen after tergite 6 yellow. End of female abdomen after tergite 6 shining black. The male genitalia were fully described and illustrated by L. Papp [2011].

DISTRIBUTION. Rare boreal-mountain species. Until now was known from Great Britain [ Chandler, 1998], France [Mr. Bruno Tissot, pers. comm., 2022], Austria, Germany, Slovakia, Switzerland [ Merz, 1997, 2004], Czech Republic [ Dvořák, 2017], Poland [ Klasa, 2002; Klasa, Palaczyk, 2016], Scandinavia ( Finland, Norway, Sweden) [ Andersson, 1990; Winqvist, Kahanpää, 2007].

In Russia, the species is recorded for the first time. It is also the first time this species has been observed for the Asian part of the Palearctic.

HABITATS. Adults of E. bicolor prefer moist forests with trees such as alder and birch, near rivers and streams. Adults are recorded from the end of May to the end of June or July (Scandinavia) and are usually observed running and resting on foliage.

In Poland, the species was recorded in the Carpathians at an altitude of 740 m, in an alder forest [ Klasa, Palaczyk, 2016]. In Czech Republic, this species was collected in spruce forest with an admixture of maple in the valley of the Pstružího stream [ Dvořák, 2017]. In the Khabarovsk Krai, all three specimens of E. bicolor were collected by sweeping in the valley of the Ikchu River with a predominance of alder tree.

Biology unknown.

Figures

Fig. 1–2. Eurygnathomyia bicolor (Zetterstedt): 1 — male in lateral view; 2 — wing. Рис. 1–2. Eurygnathomyia bicolor (Zetterstedt): 1 — самец, сбоку; 2 — крыло.