Thread subject: Diptera.info :: Brachypterous Ephydridae
#1
Can someone give me a quick pointer to what brachypterous (or in this case polymorphic) species of Ephydridae we have in Northwestern Europe. I go a small sample of smallish Ephydridae from a pitfall which superficially look conspecific, but one specimen is brachypterous. I only have a very outdated key to dive into, so if someone has a lead for me to ease my struggle...
#2
try
Philygria (including
Nostima)
semialata (Collin, 1913)
mocsaryi
nubeculosa
stenoptera
#3
None of the species David suggests has a macropterous form, as far as I know, although there are similar, related species that are macropterous (but they are not usually collected in pitfalls!
). The only genus of which I am aware that has both macropterous and brachypterous forms in the same species is
Limnellia - they are recognised by the spots on the wings. Both
suturi and
quadrata have been found as brachypterous forms (the subject of a paper which awaits completion - Oh, for a few more free days!!
)
#4
Despite what you mention, Tony, it appears they are
Philygria. I will check Hollmann-Schirrmacher's monography on Ilytheinae, that gives special reference to
Philygria.
#5
Interesting ... I wonder if these are
Philygria (=
Nostima)
picta - in this species both sexes have reduced wings, but the reduction is more extreme in the female (- sexual dimorphism rather than polymorphism). Among the
Philygria that David suggests,
semialata was originally placed in
Nostima, distingished by plumose arista and two, rather than three, dorsocentral pairs (including pre-scutellars). It is a species that is most often recorded by pitfall trapping, in Britain associated with grassy heaths.
If you have found a different
Philygria with fully macropterous and brachypterous forms, then that is certainly remarkable! In any case a good find!
#6
The specimens indeed have two pairs of dorsocentral setae and the arista has rather longish hairs dorsally. As far as I could tell (the specimens are at work and I am at home now for almost two weeks) the brachypterous specimen was a male and there were males among the other specimens as well. The fully winged specimens do not have really large wings, true, the tips just extend over the tip of the abdomen. I have not yet checked Hollman-Schirrmacher.
#7
Hollmann-Schirrmacher does not make me very happy. There is no key to all
Philygruia species but only to those with a single row of acrostichals (my specimens have none). Furthermore, there are a number of species with 'reduced wings', which I think are similar to the 'macropterous' specimens I have (wing tip then probably at level of abdominal tip). But my brachypterous specimen is truely brachypterous, so wing even further shortened and narrowed, so that the wing venation is also reduced: the major veins are the radial veins and vein M1+2 (the costa extending to that vein), but no veins posterior of that because there practically is not any wing left there. Non of the species mentioned by Hollmann-Schirrmacher seems to want to accomodate that specimen of mine.
But there is one 'maybe': One way or the other,
semialata is not mentioned by Hollmann-Schirrmacher... Due to some unclear references in the book I cannot be entirely certain why the species is not mentioned. Of the former genus
Nostima only
picta and
flavitarsis are mentioned and according to him it should be substantiated elsewhere in the book why other species (he does not even mentioned which ones) are not discussed. Possibly
semialata is one of them. Oddly enough, he mentions that THE species of
Philygria are discussed in chapter 4.5. Well, not all of them it turns out.
#8
I think Hollmann-Schirrmacher only set out to monograph
Philygria s.s.
In the process, his cladistic analysis suggested that
Nostima should be included within
Philygria, but he didn't deal with all the
Nostima species (probably not having access to
semialata among others).
From your description of the venation, they certainly sound like
semialata. Collin figured the wings in his paper in
The Entomologist - unfortunately don't have a copy here which I can scan for you. Let me know if you'd like a copy after Christmas!
#9
Do you need to ask? Yes, please!
#10
Today I received Tony's reprint in pdf format. Preliminary: The one true brachypterous specimen I have has the wign as illustrated for the
semialata female (but in my recollection it was a male). However, all other specimens have significantly larger wings than was illustrated for the
semialata male. So even if I am screwing up the sexes (plz, no comment required
) I think that the 'macropterous' specimens might be something very interesting. So,...
Anyone have material of
semialata I can study?
#11
I know I have some in alcohol somewhere (presumably yours are the same) - I may be able to sort them out next week .... (unless someone has some more accessible!)
#12
Well, the brachypterous specimen is
P. semialata, a female. Not previously recorded from the Netherlands.
The 'macropterous' specimens actually have much bigger wings than I remembered. That is probably due to the fact that the same sample also had some brachypterous Chloropidae of the same size and coloration (in alcohol all those lovely dust patterns on the Ephydridae are invisible). These 'macropterous'
Philygria were indeed
Philygria and, oddly enough, they were
P. picta, precisely the other species with two pairs of dorsocentral setae and no acrostichals. Any thoughts on what the chances would be that both occur together?
#13
Despite its widespread disribution (from Canada to Guatemala in the Nearctic and from the Azores to Japan in the Palaearctic), not much is known about the ecology of
Nostima picta . It probably has a fairly wide habitat range, so it is quite possible that both species will occur together.