Snake fly

[peterbolson]

I found this among low foliage along a woodland path.
The 4 British species can be distinguished by the patterns of their veins. Unfortunately the wings overlap in this photo so it's not that easy to work out but I think it's Phaeostigma notata. Can anyone confirm this.

Thanks

Peter

[yorkieuk]

Thats a cool looking insect

[peterbolson]

Here's a better photo



Peter

[Fauna]

Hi Peter...

Not familiar at all with these, never come across one myself (except for a fly pattern for Sea trout). But i do have a key in front of me, i've tried to go through it but i'm not quite sure of myself...but i will give it a go.

It looks good for it not to be Atlantoraphidia maculicollis.

It is also seems to fall short for Phaeostigma notata?...what i can make out is it usually has at least 12 costal veins (think yours could have 10?), they should also/usually have 2 cross veins in the pterostigma (yours has 1).

If this is the case, this would leave Xanthostigma xanthostigma an Subilla confinis, which you will need to see the hind wing to seperate.

Probably wrong with the above, but can/have you get a photo of its hind wings?

Regards Chris...

[peterbolson]

Thanks for that Chris. Sorry I haven't been able to get a shot of the hindwing
.
I've got the AIDGAP key & basically according to this if in the forewing
1) the basal vein of cell no 1 (red arrow ) is basal to the end of the pterostigma > Atlantoaphidia maculicollis or Phaeostigma notata
2) the basal vein of cell no 1 coincides with the end of the pterostigma > Xanthostigma xanthostigma or Subilla confinis. These 2 are differentiated by the hind wing veins.

With group (1) the distal vein from cell no 1 forks at the tip in P.notata but not in A.maculicollis ( blue arrow )


That's how I see it but I could be wrong . The photos aren't really clear enough. Is there any Snake fly expert out there ?

Peter

[Jason Green]

Afternoon Peter,

Did you collect and refrigerate this one, temporarily?

Take care,

Jason

[peterbolson]

Hi Jason

No, this one hasn't been in the cooler.

But I am expecting an ID from you

Peter

[Fauna]

Originally Posted by peterbolson

Thanks for that Chris. Sorry I haven't been able to get a shot of the hindwing
.
I've got the AIDGAP key & basically according to this if in the forewing
1) the basal vein of cell no 1 (red arrow ) is basal to the end of the pterostigma > Atlantoaphidia maculicollis or Phaeostigma notata
2) the basal vein of cell no 1 coincides with the end of the pterostigma > Xanthostigma xanthostigma or Subilla confinis. These 2 are differentiated by the hind wing veins.

With group (1) the distal vein from cell no 1 forks at the tip in P.notata but not in A.maculicollis ( blue arrow )


That's how I see it but I could be wrong . The photos aren't really clear enough. Is there any Snake fly expert out there ?

Peter

Yes, thats basically what i make of it...

It does say that if you keyed out to P. notata and the specimen has only 1 cross-vein in the pterostigma and less than 10 costal cross veins (which looking at it again, could have?) to have it checked against the possible fith species?

Going to bow out gracefully here Peter, as i'm usless with most winged things.

Regrads Chris...

[Jason Green]

Ah, that'll explain it. Well, I can't better what Chris has come up with (of course), all I was going to say was that prior to all that a quick parting of the wings would sort this.

I've never even seen one of 'em!

[peterbolson]

Chris, you're right about the number of costal veins - definately less than 12.

The guide says I should "send it to the appropriate person for checking", in case it's Raphidia ophiopsis !

I think I'll call it a day.

Peter