Dragons ID help please

[Dave Mac]

A couple here to ID. I think they are a femail Emporer and a mail Black Tail, but I have been completly wrong on numerous occasions in the past.
Cheers
dave

[Padfield]

I agree with you, Dave, but I have been wrong on dragons in the past!!

A male black-tailed skimmer and a female emperor, laying her eggs. Lovely!

Guy

[eccles]

The blue insect is an odd one. It's not a scarce or broad bodied chaser as the wing bases are clear. It's not a black tailed skimmer as there are no yellow spots on the abdomen. In any case the tail is blue far too close to the tip. My nearest guess is keeled skimmer but the pterostigma should be yellow. This, however a rather old looking individual so maybe that's what happens with age.

[Padfield]

But scarce chaser has dark wing bases on the hindwing, doesn't it?

My book (the comprehensive European version of Lewington) notes that the yellow spots of black-tailed skimmer eventually disappear under blue pruinescence in older males, though the black tip remains.

Guy

[eccles]

Yes. Sorry Guy, I've edited my post having checked my documentation.

[Padfield]

No apologies needed, Eccles! I always read your dragonfly posts carefully and learn from them!!

Guy

[eccles]

Thanks Guy.
Here's a black tailed. The yellow spots are not very clear in my pic, but the black extends much further up the abdomen than in Dave's photo.

2008_06_19_blacktailed_skimmer.jpg (152.82 KiB) Viewed 639 times

[Padfield]

That's a great picture and I take your point. I pass, as my information is mostly second hand! Yours seems to be first hand!

For the record, my book notes:

'Black markings and eventually yellow sides disappear under bluish pruinosity in older males', and then ' black tip is retained even in very pruinose males'.

I don't know if you know the European version of Brooks and Lewington - it's equally superb and covers all dragonflies in Europe and North Africa.

http://www.amazon.co.uk/Field-Guide-Dra ... 985&sr=8-1

Guy

[eccles]

Nope, the dark pterostigma settles it to be a black tailed as Dave originally suggested, I think. Habitat might help. Keeled are often found in boggy, acid pools. Where did you see it, Dave?

[eccles]

I haven't seen the European version of Brooks and Lewington but I have the UK/Ireland edition. Lewington's illustrations are very accurate and I was trying to see if there were any discriminating wing details on Dave's pic but the wings are very similar on the two species.

[eccles]

Got it. Looking at the Lewington illustration, the wing segments outside of the pterostigma are different, and wings are a very good indicator of species. On the black tailed they start wide, gradually decreasing in length as they approach the wing tip. On keeled they are all short because the pterostigma is longer. Fortunately this pic has good detail on the wings. It is definitely black tailed. I would guess therefore that the blue pruinescence is continually exuded, extending towards the abdomen tip as the male ages. And this one is old; they're usually gone by the end of July.

[Dave Mac]

What a great site this is. Many thanks for the informative replies and for the much needed education.
Thanks again
Dave

[Dave Mac]

Bu**er, I've just noticed the rotten spelling in my first post. Obviously Its not only in insect IDs where I need educating !

[Chris]

Bu**er, I've just noticed the rotten spelling in my first post. Obviously Its not only in insect IDs where I need educating !

"Obviously, it's not only in insect IDs that I need educating!"

My first thought was keeled, but I agree it's a black tailed

Chris