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Dragonfly help please

Posted: Sat Sep 20, 2008 8:11 pm
by Deano
Hello all.
Once again I would appreciate any assistance in identifying the attached dragonfly photo.
Thanks in advance for any knowledgable replies.
Regards
Deano.

Re: Dragonfly help please

Posted: Sat Sep 20, 2008 8:17 pm
by twitcher
Hi,
male common darter I think
Shaun.

Re: Dragonfly help please

Posted: Sat Sep 20, 2008 10:17 pm
by Deano
Thanks Shaun.
I thought it may have been a darter, but I didn't know which type.
Regards
Deano

Re: Dragonfly help please

Posted: Sat Sep 20, 2008 10:18 pm
by m_galathea
I'll leave knowledgeable replies to others, but from memory Common Darter has black and yellow stripes down its legs, and Ruddy Darter has all black legs like these.

Alexander

Re: Dragonfly help please

Posted: Sun Sep 21, 2008 7:22 am
by twitcher
Definitely not more knowledgeable,they just looked black and yellow
:roll: I need more sleep,darn those kids :lol:
Shaun

Re: Dragonfly help please

Posted: Sun Sep 21, 2008 6:04 pm
by Michael A
100% common darter

Re: Dragonfly help please

Posted: Mon Sep 22, 2008 1:49 pm
by Deano
Thank you all for your help!
Regards from Deano.

Re: Dragonfly help please

Posted: Mon Sep 22, 2008 3:57 pm
by eccles
The photo doesn't clearly show that the legs are striped like a common darter so it could suggest a ruddy darter. The apparent yellow flash on the thorax may be a bit of lens flare rather than a mark on the dragonfly. I downloaded a copy and lightened the image and the black line above the frons looks as if it descends down the sides, also like the ruddy. I wouldn't bet on it but I'm leaning towards ruddy darter. Do you have another photo?

Re: Dragonfly help please

Posted: Mon Sep 22, 2008 8:13 pm
by Deano
Thanks eccles for your info.
Yes, I do have another photo - hope this one confirms your suspicions.
Regards
Deano :)

Re: Dragonfly help please

Posted: Mon Sep 22, 2008 9:28 pm
by Padfield
The characteristic yellow mark is still visible on the thorax. I've never seen this in any picture of a male sanguineum (ruddy) and it shows up exactly like this on every picture of male striolatum (common). The frons colour looks more striolatum in the first picture too.

I'd go for striolatum and assume the legs are simply not well enough lit.

Guy

Re: Dragonfly help please

Posted: Mon Sep 22, 2008 10:01 pm
by Keith Woonton
Hi Deano,

One can seldom be one hundred percent positive with some of the more tricky identifications of what are visually very similar species but for my money I would say your pictures are of an immature male Sympetrum sanguineum - Ruddy Darter mainly because of the “wasted” apearance of the abdomin and although it is bearley decernabal in your photos, it dose apear to show the orange colouration at the very base of the wings which is absent in Sympetrum striolatum - Common Darter and to my eyes the legs apear to be plain black. The only way to be 100% positive is the vains and cell patern of the wings. But very few pictures would ever be of suficant clarity or just the right angle to make this posible.

See this link to a page discribing the Ruddy Darter on the British Dragonfly Society site, the bible of all things Dragonfly ( Horse-Stingers ) and Damselfly ( Devil's Darning Needles ) in the U K.

http://www.dragonflysoc.org.uk/sysan.html

Keith.

Re: Dragonfly help please

Posted: Tue Sep 23, 2008 11:04 am
by Deano
Thank you Guy and thank you Keith for all your information and website link, it is all very much appreciated. These insects certainly don't make their identity easily known do they!
Kind regards from Deano

Re: Dragonfly help please

Posted: Tue Sep 23, 2008 10:18 pm
by Keith Woonton
Hi Deano,

I Thought I would post these two pictures of Sympetrum striolatum - Common Darter taken 14th September for you to compare against your photo. They clearly show the yellow stripes down the legs. As you can see they are a very distinct feature of this species. Also as can be seen they do not have such a tightly “wasted” abdomen as the one in your photos,

Keith.

Re: Dragonfly help please

Posted: Wed Sep 24, 2008 5:24 am
by Padfield
I'd put money on striolatum! :D I don't think there's any doubt. Thorax trumps legs in bad light, and that first picture (Deano's) shows a classic striolatum thorax.

Guy

Re: Dragonfly help please

Posted: Wed Sep 24, 2008 10:09 am
by Neil Hulme
Hi all,
I'm 100% with Guy on this - it's definitely a Common Darter. That said, I can see exactly why the photos are causing confusion - poor lighting of the legs. If you look CLOSELY the yellow stripes ARE visible! They can be seen most clearly on the right foreleg of the first photo (and less clearly at the top of the second), and on the second and third left legs of the second photo. As Guy points out, the thoracic features also give the game away.
Neil

Re: Dragonfly help please

Posted: Wed Sep 24, 2008 10:41 am
by Keith Woonton
Guy,

As I said,

Keith Woonton wrote:One can seldom be one hundred percent positive with some of the more tricky identifications of what are visually very similar species
I think you are equally as likely to be correct with striolatum and your reasoning is also sound. It’s a shame there is not a picture of the dorsal surface, which would, I think make identification a lot more certain.
If my assessment is wrong, and it is only an opinion, I am, as always, more than happy to be corrected ( its how we learn.) And I will never get into an “I’m Right Your Wrong” type of argument over such matters which I have seen take place on this type of site.
I think Deano should be able now to make his own decision from the pointers we have all given him. Wouldn’t it be wonderful if we could both be right. In a perfect world maybe!

All the best, Keith.

Re: Dragonfly help please

Posted: Wed Sep 24, 2008 11:02 am
by Keith Woonton
OK Neil and Guy and All

The majority rules, It’s a Common.
Should I chose a pair of glasses, start reading all the literature again or chose my own blindfold before standing against a wall?

Keith.

Re: Dragonfly help please

Posted: Wed Sep 24, 2008 11:09 am
by eccles
The reason why I doubted common darter for the first pic was that the yellow thorax mark looked like lens flare. But the fact that it's present in the second photo seems to suggest that it's a common darter.
Here's a ruddy darter that I took last weekend. As you can see, the thorax lacks any yellowish markings, the black border around the frons runs down the edge, the abdomen is waisted (note, not wasted ;) ), and the legs are black.
DSC06597.jpg
DSC06597.jpg (154.07 KiB) Viewed 1248 times

Re: Dragonfly help please

Posted: Wed Sep 24, 2008 11:29 am
by Padfield
Keith Woonton wrote:Should I chose a pair of glasses, start reading all the literature again or chose my own blindfold before standing against a wall?
None of the above. Just wait for us to make a mistake, which we will, and then mock mercilessly! :D

G

Re: Dragonfly help please

Posted: Wed Sep 24, 2008 1:27 pm
by Neil Hulme
Hi Keith,
No glasses needed! I think dragonflies can be VERY difficult to identify, especially from photographs that might obscure diagnostic features. When I first looked at the photos I thought the legs were black - you really have to squint before the yellow stripes appear. And the pale patch on the thorax (before confirmation in the second pic) could easily be lens flare. These debates are very useful, as the arguments 'for' and 'against' are probably a better way of helping others with future 'I.D.' than even the better guides with photos and extensive descriptive text.
Neil