Megaselia brevior complex

The genus Megaselia Rondani (Phoridae : Diptera : Insecta) is one of the largest genera known (with about 1400 species described). One group with particularly difficult species recognition are those that are 1-2 mm long, with a bare mesopleuron, the wing with a shortened costa and the haltere knob yellow.

Megaselia brevior complex (Phoridae : Diptera)
Males of the Palaearctic species of the Megaselia brevior complex Geographic Scope: Palaearctic — Audience: taxonomists — Collaboration: open — Status: under construction, needs checking — Edited by: G. Weber

1		Vein 3 unforked    Megaselia abludens (Schmitz, 1927)
1	*	Vein 3 forked    ► 2
2	(1)	Hind femur yellow with sharply contrasting dark apex    ► 3
2	*	Hind femur variously darkened, and if basal half is dirty yellow it only gradually darkens towards apex    ► 4
3	(2)	Anterior spur of hind tibia < half as long as posterior (ventral) spur and clearly less robust. Labella of proboscis enlarged and with dense fields of numerous short pale spines below. Dorsal face of epandrium about two-thirds of lower margin of left side    Megaselia pygmaea (Zetterstedt, 1848)
3	*	Anterior spur of hind tibia at least 0.7 times as long as posterior spur and almost as robust. Labella not enlarged and with only a few short pale spines below. Dorsal face of epandrium only about half length of lower marin of left side    Megaselia curtineura (Brues, 1909)
4	(2)	Notopleuron with 3 bristles. (Costal index > 0.38. Costal cilia > 0,08 mm)    Megaselia laeviceps Schmitz, 1948
4	*	2 notopleural bristles    ► 5
5	(4)	Left lobe of hypandrium vestigial, hairs on tip of proctiger distinctly more robust and a little to clearly longer than those on cerci    ► 6
5	*	Left lobe of hypandrium evident    ► 8
6	(5)	Veins 4 and 5 subparallel in middle third    Megaselia stenoterga (Disney, 1988)
6	*	Veins 4 and 5 divergent throughout    ► 7
7		Wing membrane slightly darker (view against a white background). Hypogyg as in Fig. 7a    Megaselia oxybelorum Schmitz, 1928 7a: Megaselia oxybelorum, Hypopygium left, image composed of 5 exposures with different focus 7b: Megaselia oxybelorum, Hypopygium right, image composed of 4 exposures with different focus			7a
7	*	Wing membrane virtually colourless. Hypogyg as in Fig.++    Megaselia parvula Schmitz, 1930
8	(5)	Hairs on tip of proctiger distinctly more robust and a little to clearly longer than those on cerci    ► 9
8	*	Hairs on tip of proctiger at most subequal to those on cerci    ► 10
9	(8)	Labella of proboscis enlarged and with dense fields of numerous short pale spines below    Megaselia berndseni(Schmitz, 1919)			9a
9	*	Labella not enlarged and with only a few short pale spines below.    Megaselia leucozona Schmitz, 1930
10	(8)	Hypopygium as in Figs. 10a and 10b, with left lobe of hypandrium long and bent    Megaselia brevior (Schmitz, 1924) 10b: Drawing based on Fig. 1 in: Disney, R.H.L. (2006): Revision of the Palaearctic members of the species complex resembling Megaselia brevior (Schmitz) (Diptera: Phoridae). Fragmenta Faunistica 49(1): 41-51			10a
10	*	Hypopygium otherwise, left lobe of hypandrium shorter    ► 11
11	(10)	Hairs at tip of proctiger shorter than hairs on cerci and left lobe of hypandrium short (Fig.++)    Megaselia angustiata Schmitz, 1936
11	*	Hairs at tip of proctiger subequal to all but the longest hairs on cerci and left lobe of hypandrium longer(Fig.++)    Megaselia brevissima (Schmitz, 1924)

Source: Key derived from keys in: Disney, R.H.L. (1988): The Palaearctic species resembling Megaselia pygmaea (Diptera, Phoridae), including two new species. Annales Entomologici Fennici 54: 153-161.
and
Disney, R.H.L. (2006): Revision of the Palaearctic members of the species complex resembling Megaselia brevior (Schmitz) (Diptera: Phoridae). Fragmenta Faunistica 49(1): 41-51.