Saturday, 12 May 2012

Curiouser and curiouser

Two of my recent posts have shown the results of my research on eggs and insects in Juncus rushes, and a great deal of additional background research has been taking place in the interval since those posts were made. In order to keep things neat and tidy, I'll be reproducing a couple of images from those posts in the report that follows.

Firstly, on 29th March, I showed these eggs:

Leafhopper eggs in Juncus

These have been identified as leafhopper eggs, but the species is still undetermined. Two species of leafhopper are known to associate with Juncus: Cicadella viridis and Conomelus anceps.

On 22nd April, I showed this dead specimen of Conomelus anceps:

Conomelus anceps killed by Entomophthora petchii on Juncus effusus
I was able to get a very accurate description of the Conomelus eggs from the UK expert on such matters and after some exhaustive searching, I managed to find a sample of Conomelus eggs from the Juncus:

Conomelus anceps eggs in Juncus
From the scale of the image, it can be seen that these eggs are very much smaller than the original leafhopper eggs from March. It's also worth pointing out that while the original eggs are in a line of 15 eggs, the Conomelus eggs are laid in smaller batches of 4 or 5.

Cicadella viridis is a much larger leafhopper than Conomelus anceps, but it turns that although C. viridis feeds on Juncus, it lays its eggs in the bark of thin-barked trees, so the identity of the original leafhopper eggs still remains a mystery.

In more recent pursuit of the owner of the original eggs, I have found other species and other eggs. This latest set of eggs is most bizarre:

Conomelus anceps eggs (A)

Arrow 'A' shows a couple of Conomelus anceps eggs, but the multicoloured eggs are, again, in a straight line (and are larger). The varied colours and shapes of these eggs suggest that they have been parasitised - presumably by minute parasitic wasps. So I think this image shows two sets of eggs: the Conomelus eggs on the left and a parasitised row of the original eggs which still remain unidentified.

Arrow 'B' points to a particular egg which caught my attention. It seems to show a nymph of a leafhopper of some kind, so that is my current area of research. I've blown up that part of the image here:


It looks to me like a leafhopper nymph looking directly towards the camera. Time (and a great deal of further research) will tell.

3 comments:

Caroline Gill said...

Amazing research and investigation here, Stuart. Your blog is often a first port of call when I find unusual insects!

Gill said...

I agree - it does look like a leafhopper looking out at us - whether or not it's parasitised is anybody's guess - my gut reaction is not, but the orangey ones are. Fascinating to see what emerges....

Toffeeapple said...

This is turning into quite a detective story, I hope you manage to get a definitive answer.