Thread subject: Diptera.info :: Sphaeroceridae with strange wings from Gotland, Sweden
Posted by Johane on 15-07-2016 21:41
#1
Hi!
I wonder about this Sphaeroceridae. The hind edge of its wings is curved inwards and has long hairs. Are there many species that have this feature and what is it used for?
Edited by Johane on 15-07-2016 21:49
Posted by John Carr on 16-07-2016 00:16
#2
Males of
Coproica acutangula have that curled-under wing. See comment by Matthias Buck here:
http://bugguide.n...83/bgimage.
Posted by Johane on 24-07-2016 13:59
#3
Thanks John! Does anyone know what its function is? Display perhaps?
Posted by Jan Willem on 25-07-2016 19:49
#4
Recently I also found a male of this species with such peculiar "winglashes". I'm also curious about the function.
Edited by Jan Willem on 25-07-2016 19:50
Posted by Paul Beuk on 26-07-2016 07:53
#5
I found scores of them over the past few years on horse manure and in horse stables. Function? Perhaps something in courtship display. Difficult to observe in these tiny critters that usually are surrounded by many others (specimens and species) around the manure.
Posted by Tony Irwin on 26-07-2016 09:23
#6
In many small flies, the males (and occasionally the females) vibrate their wings rapidly to produce "songs" to impress potential mates. If
Coproica males "sing", it may be that the marginal bristles on
acutangula males give their songs an enhanced tone or timbre. A great little project for someone with high resolution high speed camera and a large supply of horse poo!
Posted by Jan Willem on 29-07-2016 10:35
#7
I received some interesting information on this topic from Jindrich Rohacek:
the curved hairs on emarginated male wing of C. acutangula (note: also discal cell is modified due to this emargination) serve during copulation to better hold the female wing; in other sphaerocerids the male mid leg is often modified for the same purpose (combs of curved setae or spines on tibiae and femora, curved tibia, see extreme case - Limosina silvatica), also the ventral hook on hind femur in Crumomyia nitida may serve similarly. There are also vice-versa modifications, e.g. in Phthitia empirica the 2nd costa sector (Cs2) of female wing is modified because the male holds by its armed middle legs the female wings just in Cs2.