20.a. Surstylus: large tooth accompanied SPHEGINA by a small tooth at the base, large tooth somewhat narrowed towards base (fig- ure 722); hairs on lateral margin of ter- Introduction gites 3-5 pale, in melanistic specimens intermixed with a few black; tergite 2-4 Sphegina inhabit shaded areas in damp with pairs of spots, which may touch in coniferous and deciduous forests, in asso- the middle. 7-10 mm. Europe, Siberia › ciation with running water. Adults fly Sphaerophoria interrupta (Fabricius) (= through the vegetation and are found vis- Sphaerophoria menthastri auct.) iting flowers of white umbellifers and 20.b. Surstylus: small tooth at the base of other flowers along the forest edge. The the large tooth absent, large tooth grad- larvae have been found in wet, sappy ually widened towards base (figure 731); material beneath a patch of wet bark on a hairs on lateral margin of tergites 3-5 living Ulmus (Hartley, 1961). Larvae have black; tergites 2-4 with yellow bands. 7- also been found under the bark of water- 10 mm. Northern Europe, mountains of logged branches of various deciduous Central Europe › Sphaerophoria laurae trees and in sap runs on Quercus (S. clu- Goeldlin de Tiefenau nipes by Rotheray, 1990) and Ulmus (S. elegans and S. verecunda, by Hartley, 1961), see Speight (2003). SPHECOMYIA Recognition Sphegina are slender, elongate flies. Their Introduction abdomen is claviform with segment 2 elongate and segments 3 and 4 broad- Sphecomyia are rare, boreal hoverflies that ened, a feature especially prominent in live along rivers and streams in boreal the female. Their colour is usually dark, forests. These large, yellow and black hov- even blackish. Some species have large erflies are excellent mimics of social wasps. reddish markings on tergites 3 and 4. S. sibirica has a yellow colour form. The key is based on Thompson and Torp (1986), Key Doczkal (1995), Vujic (1990) and Kassebeer (1991). 1. Only a single species in Europe. Face yellow with black stripe; tergites black with yellow bands. 12-14 mm. Northern Europe, Northern Siberia › Sphecomyia vespiformis Gorski Jizz: remains a convincing wasp mimic even when pinned!
figure 732. Sphegina clunipes, thorax from figure 733. Sphegina sibirica, thorax from below (Verlinden). below (Verlinden).
209 Key 6.a. Hind coxa partially pale, yellow to orange › 7 1.a. First sternum not reduced, wider than 6.b. Hind coxa dark, brownish to black; long, oval (figure 732 › 2 frons with long black hairs, with some 1.b. First sternum greatly reduced (and hairs longer than 3rd antennal segment longer than wide) or absent (figure width. 6-7 mm. Northern Europe and 733); face and humerus black; katepis- mountains of Central Europe, Siberia › ternum shiny. 7-8 mm. Northern, Sphegina spheginea (Zetterstedt) Western and Central Europe, Siberia, extending its range › Sphegina sibirica 7.a. Antenna pale orange; subcosta joining Stackelberg costa before r-rm crossvein (figure 738); Jizz: specimens black to yellow (var. flavescens) surstyle narrowed and pointed apically with all intermediates. (figure 740). 5-7 mm. Central Europe › Sphegina nigra Meigen (= Sphegina 2.a. Katepisternum dull, grey pollinose, at clavata Scopoli) most upper margin shiny › 3 2.b. Katepisternum shiny, without polli- nosity; hind coxa black; face usually entirely black. 5-6 mm. Northern and 735. Central Europe › Sphegina montana Becker 3.a. Tibia 2: not expanded (figure 749), male: tibia 2 not expanded, if some expansion appears then legs 1 and 2 blackish extensively dark; female: tibia 2 of equal width over its length, at apex at most with some brownish bristles › 4 3.b. Tibia 2 expanded on distal 1/2, male: greatly expanded on apical 1/4 (figure 734), female: expanded on apical 1/2 736. and with dense black bristles at the apex. 7-9 mm. Elevated parts of Central Europe › Sphegina platychira Szilady 4.a. Males (eyes separated, check for gen- italia) › 5 4.b. Females (females of S. claviventris not yellowish known) › 13 5.a. Face entirely dark brownish to black (figure 735) › 6 5.b. Face pale yellow to orange on ventral 737. 1/4 or more (figure 736, figure 737) › 8
yellowish
figure 735. Sphegina verecunda, head of male. figure 736. Sphegina elegans, head of male. figure 734. Sphegina platychira, leg 2 (after figure 737. Sphegina clunipes, head of male Van der Goot, 1981). (Verlinden).
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