Damselflies for Identiification

[balkantrek]

I photographed these two damselflies at kew Gardens last June but still haven't been able to come upe with a positive identification.

I have tentatively labelled them as:
1. Common Bluet (Enallagma cyathigerum) female
2. Common Bluetail (Ischnura elegans) female

Can anyone please confirm or correct this.

[Wild-Woman]

I agree Cmmon Blue for the first but the second, in it's teneral state is harder. Perhaps long bodied enough for Large Red but not sure.

[LindaB]

Im pretty certain the second one is not a Large Red damsel as they have a distinct amount of red on the abdomen well before they reach that stage.

I cant help with any suggestions either though.

[balkantrek]

Thanks for your replies. I think the identity of the second damselfly may remain inconclusive.

I hope to go back to Kew Gardens again later this year and get some more dragonfly and damselfly photos. The gardens seemed to be a paradise for them.

I found this interesting document about the dragonfles of Kew:
http://www.kew.org/ksheets/pdfs/k23dragonflies.pdf

[Dogghound]

Looking at the amount of black thats already present on the thorax, the shape of the humeral and antihumeral stripes suggests this is Enallagma cyathigerum too.

Certainally not large red or the similar Coenagrion species.

[RoyW]

Originally Posted by balkantrek

I have tentatively labelled them as:
1. Common Bluet (Enallagma cyathigerum) female
2. Common Bluetail (Ischnura elegans) female

Can anyone please confirm or correct this.

I would agree with the species ID on both of these, but the second individual is a teneral male not a female.

As has already been said, the identification of damselflies that have very recently emerged from their larvae is not easy (and I would generally recommend that you don't even try until you are very familiar with more mature damselflies!).
This one can be identified as a male by the swelling visible under the second abdomenal segment, and by the absence of an ovipositor under the tip of the abdomen. Species ID is much trickier - but several features point to I. elegans including the abdomenal appendages, visible pattern on thorax and abdomen, and what appears to be a projection on the prothorax (just behind the head). These features may be clearer (and more conclusive) on a higher resolution image.

Roy.

[Dogghound]

I couldnt see the projection so ruled out Ischnura. You must have better eyes than me i'll take your word for it.

[RoyW]

Originally Posted by Dogghound

Looking at the amount of black thats already present on the thorax, the shape of the humeral and antihumeral stripes suggests this is Enallagma cyathigerum too.

Certainally not large red or the similar Coenagrion species.

If the second image is not I. elegans, then E. cyathigerum is the only other possibility. IMO the shape of the humeral and antehumeral stripes is difficult to judge properly because of the angle (slightly from below). In this shot the dark humeral stripe looks a bit narrow for most Ishnura, but the pale antehumeral stripe looks a bit too narrow for Enallagma!
There does appear to be the start of a second dark 'spur' on the side of the thorax, and the dorsal side of the abdomen looks largerly dark though - both of which point to I. elegans.

[RoyW]

Originally Posted by Dogghound

I couldnt see the projection so ruled out Ischnura. You must have better eyes than me i'll take your word for it.

I would certainly like to see a higher res image to be certain that this feature is there!

[Dogghound]

Me too Roy. I completely agree with what you are saying . Not easy in photos these fresh specimens.