Diptera.info

Posted by Stephen R on 29-03-2011 16:59

3-mm, Clitheroe UK, 28 March 2011

This smaller species arrives convincingly at the lyneborgi/minuta couplet, and from the cercal plate and surstyli it looks very like minuta. What should I check to make sure it isn't E. suwai?

Edited by Stephen R on 02-04-2011 13:14

Posted by javanerkelens on 29-03-2011 20:04

By change i got today a Egle minuta by post (from Dick Belgers) and it was nice to see.(New for the Netherlands) Comparing it to your fly i don't think it is E.ciliata. Also we can see long pv on the hind femur, so likely again E. rhinotmeta.
The differents between E.lyneborgi / suwai are really difficult to make .
E. lyneborgi = Surstyli in lateral view relatively broad. Apical extension of cerci often somewhat tapering on distal third. Pstgonite without anterior transverse edge.
E. suwai = Surstyli in lateral view relatively narrow. Apical extension of cerci not tapering on distal third. Postgonit with anterior transverse edge.
(ref: Revision of the willow catkin flies, genus Egle from V.Michelsen)

I show also a photo of the genitals from E.minuta i made today..(not very sharp, but genitals where less then a millimetre)

Edited by javanerkelens on 29-03-2011 20:05

Posted by Stephen R on 30-03-2011 00:01

I'm sure it's not E. rhinotmeta. Comparing the specimen, the setae in the photo are anterior to the femur and look longer because they project forward. The pvs are much shorter and don't show in the picture. Anyway, there's no group of bristles by the st5 processes.

I'm attempting a proper genital preparation so I can get a better look. At the moment it looks very like yours. Congratulations on the photo - I don't think I'll be able to do that!

Posted by javanerkelens on 30-03-2011 12:43

Maybe it could be Egle parva.
The parafacial seems about same width as postpedicel and lower margin seems also projected.
Egle minuta has the parafacial much smaller and lower marging only slightly projected.
Hindfemur of E. parva has more pv than E.minuta

I made some photos of the hind and midleg of E.minuta, so maybe you can compare.
But keeps difficult with those little one's, they are very simular ,also on genitals!

Posted by Stephen R on 30-03-2011 18:16

I'm really struggling with this one! The genitalia are not any easier to see now they are completely transparent - I don't know how you managed that photo; did you take it through the microscope? I still think they look like the drawings for E. minuta: the cercal plate strongly waisted and the surstyli with the thumb-like step on the inner edge (E. parva doesn't seem to have this). I haven't yet managed to separate out the internal bits, but I'll keep trying. Should have started on something bigger!

Here is a photo of the specimen I am examining in case I've got mixed up and it isn't the one in the live photo. I see what you mean about E. parva, and I was a bit uncertain about the 'single row of hairs' on the gena in Michael's key, as the ones on mine are not in a neat row at all. The tibiae don't look too different from yours if I put them at the same angle. I find the facial measurements tricky because they are so dependent on view point.

Edited by Stephen R on 30-03-2011 18:28

Posted by javanerkelens on 30-03-2011 22:05

Hmmm....do I see very dark haltares on this photo ?
And does the analvein reach the costa .....or does it seems so....?
Did you check also for Drymeia (Muscidae).....
Maybe it is possible to make a drawing of the genitals (does not have to be like.. a Rembrand..)

Posted by Stephen R on 30-03-2011 23:08

Yes, the anal vein does reach the margin, though it gets a bit faint. I think the halteres have darkened with drying (perhaps because the fly was quite newly emerged).

I'm not sure if I've still got the genitals - keep losing them - but I'll have another look tomorrow and do a sketch.

Posted by Stephen R on 31-03-2011 12:35

No, I took the maceration/dissection too far and it's all unrecognisable :(. All I can say is that they looked very much like the ones you showed and like the illustrations for E. minuta. If the habitus is wrong, it will have to stay uncertain until I can collect more. Not much chance in today's weather. If I can, I'll send you one, Joke. Thanks for your help Joke and Oxycera!

Posted by javanerkelens on 31-03-2011 15:24

#10

Don�t give up the hope!

Next time, just again cut of the last part of the abdomen, put it in a small box and pour some boiling water on it and put it all away for one day.
Then the genitals are weak enough.
Take it all then into a box with only the bottom a little wet, so the genitals keep wet and not dry up�. (not to much water otherwise the genitals keep turning in the water!)
Then you can separate the important parts with a needle and pair of tweezers.
Put the genitals afterwards in alcohol.
(I use KOH to soften the genitals, but with boiling water it mostly also works)

And of course�you always can send me some species!:)

Edited by javanerkelens on 31-03-2011 15:26

Posted by Stephen R on 01-04-2011 23:56

#12

Now I feel a bit better B).

I've prepared a nice pickle for you, Joke. Two males like this, one like E. rhinotmeta and lots of assorted females for company. Put your address in a PM and I'll send it :).