Thread subject: Diptera.info :: Common South Asian Micropezid fly with white tarsi

Posted by Elaphrornis on 21-03-2013 03:38
#1

This request concerns a very common Micropezid fly (either one widespread species or several closely related species in the same genus) in South and Southeast Asia, pairs of which are often seen in copula. All three pairs of legs have white tarsi. The remaining segments of the middle and hind legs are yellowish brown but in the forelegs the distal half of the femur and the tibia are dark which makes the white tips of the forelegs appear more conspicuos. The forelegs are held raised and moved constantly like antennae (e.g. such as the antennae of an ichneumonid wasp). For quite some time I have assumed this fly to be a species of Mimegralla, perhaps Mimegralla coeruleifrons (Macquart 1843) but I must confess I cannot now recall what led me to this conclusion (perhaps comparison with photos identified as Mimegralla species). I am aware that there is a Mimegralla species named Mimegralla albimana (Doleschall, 1856) widespread in Southeast Asia and the Pacific (this or a related species is sometimes named "white sox fly": http://cookisland...p?id=13975), which evidently refers to the conspicuous white tarsi. I would appreciate any comments on my tentative identification of the common species of South Asia (e.g. Sri Lanka) as shown in the photograph below and any references to keys or descriptions that may help in specific determination.

farm9.staticflickr.com/8461/7922068384_25d2d2c589_o.jpg

Posted by John Carr on 21-03-2013 22:07
#2

It does resemble Mimegralla albimana. Do veins R5 and M meet or reach the wingtip separately?

Use caution considering superficially similar flies as belonging to the same species in Taeniapterinae. In North America we have two similar species that are placed in different genera, both with neotropical relatives.

Edited by John Carr on 21-03-2013 22:08

Posted by Elaphrornis on 22-03-2013 02:29
#3

Unfortunately I don't have access to specimens since am not currently in Asia, so cannot check on wing venation. Yes, I realize the danger of IDing based on superficial similarity but the flies I have in mind must belong to a single genus even if they don't represent a single species. Whether the genus is Mimegralla remains to be confirmed. The following paper might be relevant; I have not seen it:

McAlpine, D.K. 1998. Review of the Australian stilt flies (Diptera: Micropezidae) with a phylogenetic analysis of the family. Invertebrate Systematics 12(1): 55-134.