Myopa


Myopa testacea (M. van Veen)

 

Introduction

Myopa are brownish to blackish Conopids, which are immediately recognized by the large, inflated and whitish face, which extends far below the eyes. They are found near all kinds of flowering plants. M. tesselatipennis is often taken from flowering scrubs like Craetegus, where they sit on the twigs, on the hunt for hosts for their larvae. Others, like M. buccata, are also found visiting flowers of herbs, like Taraxacum. Their larvae are endoparasites of bees, bumble bees and wasps (Vespula vulgaris).

Recognition

Stuke (2001) delineates the differences between M. fasciata and M. curtirostris. Stuke and Clements (2008) revise the testacea group.

Key

1.a. Wing hyaline, without black markings, sometimes yellow or white near base -> 2

1.b. Wing with black markings: cross vein at the basis of cel R blackened, that cross vein blackened with additional black patterning on other veins, cell R with black patch or wing with black and white patterning -> 7

2.a. Face: at the mouth edge left and right a thin black stripe; tergite 4 and 5 with silvergrey dusting, at the front border with two large, dark rectangular spots without dust, these spots well separated. 6-8 mm. NL, B, D. -> Myopa variegata Meigen

2.b. Face: mouth edge white, without black stripes; tergite 4 and 5 either without dust or largely dusted, if dusted than the dustless spots at the front edge semicircular and not well separated -> 3

3.a. Scutellum black; abdomen blackish with brown edges, for M. fasciata with yellowish dust -> 4

3.b. Scutellum reddish; abdomen reddish brown (like a broad Sicus). 11.5-15 mm. NL, B, D. -> Myopa dorsalis Fabricius

Myopa dorsalis, originally mistaken for a Sicus
Myopa dorsalis.

4.a. Wing: anal cell long; face under eyes bare -> 5

4.b. Wing: anal cell short, as in Dalmannia; face under eyes haired. 3.5-4 mm. D. -> Myopa morio Meigen

5.a. Femora orange to brown, with or without dark patches, along underside without or only with weak black bristles; antennae: segment 2 1.5 times as long as segment 3 (measured on the outside); more red-brown species, but thorax and abdomen can be largely black above; snout shorter or longer than head -> 6

5.b. Femora black (sometimes paler at very tip), at the underside over the full length with many strong, short, black bristles; tibiae brown at base, black at tip half; antennae: segment 2 at most as long as segment 3 (measured on the outside), arista pale at base and black at tip half; thoracic dorsum uniformly black and weakly dusted without longitudinal lines of dust, contrasting with humeri which are densely silverish dusted; abdomen largely blackish with variable brown pattern at the sides and with silver dust on hind and side margins of tergites; snout shorter than height of head. Small species: 4-5 mm. Central and Southern Europe. -> Myopa occulta Wiedemann in Meigen

6.a. Frons: black pattern in V-form, leaving the frons next to the compound eyes pale; Femur 1 brown with a dark patch at the outside; antennae: arista pale at base and black at tip; tergite 2 with broad brown side margin; tergite 4-7 covered with dust over much of their surface, at tergite 4-5 often (but not always) with half round undusted spots at the front border; thoracic dorsum with two well defined longitudinal stripes of dust at the side margin and 2 stripes on the centre. 7-10 mm. NL, B, D. -> Myopa fasciata Meigen

6.b. Frons: black pattern in W-form, frons next to compound eyes dark; femur 1 brown without dark patch at the outside; antennae: arista uniformly pale; tergite 2 black, only brown at the very side margin; tergite 4-6 dusted over a small part of their surface, tergite 7 undusted; thoracic dorsum weakly dusted, without longitudinal stripes of dust. 5-8 mm (extrapolating the differences in thorax width of Stuke (2001) to body length) -> Myopa curtirostris Kröber

7.a. Cross vein at basis of cell R blackish -> 8

7.b. Cross vein at basis of cell R whitish; wing with a mix of white and black spots. 6-11 mm. NL, B, D. -> Myopa buccata Linnaeus

8.a. Wing: cell R without a black spot in the centre, but with black infuscations around some of its veins; snout shorter than M. picta -> 9

8.b. Wing: cell R with a black spot in the centre; snout very long. 8-11 mm. B, D. -> Myopa picta Panzer

Myopa picta, kop
Myopa picta, head (from Kröber)

9.a. Thoracic dorsum: black coloration extends all the way up to the base of the scutellum, at least medianly -> 10

9.b. Thoracic dorsum: black coloration does not extend to the base of the scutellum, thoracic dorsum brownish red just before the scutellum ->12

10.a. Cross vein at basis of cell R is the only clear black marking in the wing, sometimes accompanied by weaker dark infuscations around the veins of cell R; wing: basal cells without white to yellow patches -> 11

10.b. Wing: multiple, well marked black patches in the wing in addition to the black basis of cell R, basal cells with some white to yellow patches. 7-8 mm. NL, B, D. -> Myopa polystigma Rondani

11.a. Male: tergite 4 undusted or at most dusted medianly on the hind margin, not reaching front margin at the sides. Female: tergite 4 largely undusted, at most dusted in posterior half or less. Both: tergite 5: front margin undusted; wings often (but not necessarily) weakly infuscated along length veins. Abdomen dark orange to blood-red.  6-11 mm. NL, B, D. -> Myopa testacea Linnaeus

11.b. Males and females: tergite 4 dusted medianly from the posterior margin for at least half its length and dusting may reach front margin at the sides, tergite 5 medianly dusted for its whole length, often completely dusted; wings: hyaline of uniformly tinted not infuscated along length veins in addition to blackened base of cell R; Abdomen dark reddish brown. 4-6mm.  Myopa stigma Meigen

Jizz: can be confused with small specimens of M. testacea if dusting is vague. Stuke and Clements (2008) note that M. stigma has two dusted longitudinal stripes on the thoracic dorsum, which lack in M. testacea, but like to test it further.

12.a. Abdomen: tergite 5 with long hairs, which are at least as long as the largest diameter of tibia 3, the long hairs at tergite 5 perpendicular on or with an angle of 45 degree to the surface -> 13

12.b. Abdomen: tergite 5 with short hairs, which are shorter than (at most some as long as) the largest diameter of tibia 3, at tergite 5 the hairs at an angle of 45 degree to the surface -> 14

13.a. Tibia 1 and 2: at the underside, at the basis with a row of appressed, black bristles, forming a black line on the pale surface, longest hairs on tibia 1 and 2 as long as the width of the tibia (at its widest point); tergite 5 densely haired, with hairs at an angle of 45 degree. 7-9 mm. NL, B. -> Myopa hirsuta Stuke (=Myopa strandi Collin)

Jizz: abdomen darker, blood-red in coloration.

13.b. Tibia 1 and 2: without a row of black appressed bristles (the only Myopa which lacks these hairs), longest hairs on these tibia much longer than the width of the tibia; tergite 5 with hairs at an angle of 90 degrees. 7-9 mm. NL, B, D. -> Myopa vicaria Walker

Jizz: abdomen paler, yellowish orange in coloration.

14.a. Palpae, at the basis of the snout, brown (contrasting with white mouth edge); snout: 3rd part shorter than 2nd part. 7-10 mm. NL, B, D. -> Myopa tesselatipennis Motchulsky

14.b. Palpae whitish (hardly contrasting with white mouth edge); snout 2nd and 3rd part equally long, each longer than tars 1. 8.5-10 mm. NL, B, D. -> Myopa pellucida Robineau-Desvoidy (=Myopa extricata Collin)

Literature

Stuke J.-H. and Clements D.K. 2008. Revision of the Myopa testacea Species-Group in the Palaearctic Region (Diptera: Conopidae). Zootaxa 1713: 1–26.

Van Veen M. 1984. De Blaaskopvliegen en roofvliegen van Nederland en België. Jeugdbondsuitgeverij, Utrecht.

Last updated 31.03.2010