Sunday 7 June 2015

Emerald Damselfly Dilemmas!

After making a visit to a private site south of Reculver yesterday and posting some shots last night, I had a message from Adrian Parr to let me know that the Emerald shot I posted was indeed the rarer Scarce Emerald Damselfly. I had found a single female Scarce Emerald Damselfly at this site last year in among the near three figure count of Emerald Damselflies so when I found this individual, I thought that it was most likely an Emerald Damselfly. As with a lot of damselflies, they can be very tricky to tell apart and although the mature adults are a lot easier, immature male and females can be quite hard to identify as I have found out in this instance. Their patterns and colour can change and this all adds to the challenge of trying to identify them. I have posted below 2 of the shots from yesterday of the female Scarce Emerald which show some of the features as Adrian points out: 

the isolated spot on the thorax should still be there in teneral Emerald Damselfly, and the lateral lobe of the prothorax should be all-pale, whereas your individual has it pale below, but metallic green above. Another feature that I've not seen in the guidebooks - probably because it gets obscured with age - is the suture/join between the top and side plates of the main thorax. This is thinly outlined pale in Emerald Damselfly (though not as noticably as in Southern Emerald), while in Scarce Emerald Damselfly such markings are generally absent and the suture is thus very inconspicous. Hope this helps, I'm fairly sure it's right .


Scarce Emerald Damselfly (female) 

With this in mind, I made another visit this morning in the hope of grilling any Emerald Damselflies that I could find. I arrived about 7.30am and set about walking through some of the long grasses on the waters edge and it wasn't long until I flushed an Emerald. I was soon looking closely at the features needed but because it was an immature male, to be honest, I struggled. I took the shot below before it flew off out of view. I don't know if it can be identified from this shot alone?

Emerald Damselfly sp (male)

I carried on looking and nearby found another Emerald Damselfly species. This time it was a female and she was a little more cooperative and I was able to take a few shots and try to capture some of the features needed. This individual did look a little more 'chunky' and as she posed with wings opened, I could see the square spots on segment 1, a key feature for the Scarce Emerald Damselfly. These are pear shaped in the female Emerald Damselfly.

Scarce Emerald Damselfly (female)

I also could not see the isolated spot that Emerald Damselfly shows on the side of the thorax and the only problem I had was the length of the ovipositor, is it long enough?

Scarce Emerald Damselfly Ovipositor (long enough?)

With the square spots on segment 1 and chunky size, I feel that this is another female Scarce Emerald Damselfly. Please feel free however to correct me if I am wrong. If it is, perhaps there is a small colony building up at the site. That would be fantastic for this nationally rare species to be getting a foot hold in East Kent. Whether I am right or wrong, it was certainly another learning curve to try and identify these tricky damselfies and hopefully, a bit more knowledge learnt. I shall hopefully return throughout the next few weeks to see them mature up and possibly, find a mature male to photograph soon. 

Scarce Emerald Damselfly (female)

8 comments:

  1. Excellent find Marc. Hope the colony carries on growing. Good to hear the Norfolk Hawkers are still around as well.

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    1. Thanjs Bob. As far as I know, tge Norfolk Hawkers have not energed yet at Westbere. I shall try a look after work this week.

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  2. Sounds like everything is starting to emerge there now Marc, still not much dragon action here yet. love those images today!

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    1. Cheers Warren. All the winter months with not much to do and now theres too much and not enough time. Better that way I suppose.

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  3. Hello Marc, stunning captures and the details are amazing.
    Regards,
    Roos

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    1. Many thanks Roos for your comment. Touch wood, the camera work seems to be ticking along nicely at the moment.

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  4. Awesome looking creatures, they look like they're wearing green coloured metal armour. Super shots Marc.

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    1. Thanks, Ian. Like you, I think they look superb, especially when those wings look nice and fresh.

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