Friday, July 19, 2013

Waspish behaviour and bad eggs...

When I found a clutch of bug eggs a while ago,I thought that I might be able watch them emerge and then observe some of their behaviour in an effort to learn more about them. I didn't realise at the time that the greyish appearance was to be a clue as to just how wrong I was....




What actually emerged a few days later,was this tiny parasitic wasp. In fact, each little egg had the very same occupant. I know that Trissolcus basalis is a parasite of the green shield-bug, but they are so small that I couldn't say with any confidence if that's what we are looking at here.

I decided that a concentrated search for another batch would be in order...


Sometimes...just sometimes, things go as planned. A couple of days later I found this batch of eggs on oak. This time they looked much more promising.

I didn't have long to wait before the tiny bug nymphs began to emerge en-masse...

Click on any photo for a larger view

I also didn't have long to wait to learn something new about the critters...


All 26(?) of them changed from green to brown in a very short space of time. How strange when they would become green once again at the very next stage of development?

Incidentally,isn't it wonderful how symmetric the egg laying is here...rows of 3 then 4 then 5 then 6 then 5 then 4....

They were ready to moult in no time at all and I was lucky enough to be there when a couple did just that...



An amazing thing to witness. Firstly look how large it has already become compared to the exuvia (external skeleton) it is leaving behind. Then see how the insect that is emerging is so pale and almost translucent.

I wanted to show you the large image above because it's such a spectacular thing to see. Here's a set of shots now that give you more of an idea of the emergence process...







Eventually..it breaks free of the old 'skin' completely...


And a shot of it sitting,no doubt exhausted by the effort,beside the Exuvia ...


Does it sound too crass to say that it is quite moving watching something so tiny go through this process that allows it to grow ever larger? It seems a real struggle for the bug and yet-it has no choice,it must undergo this change repeatedly, until it becomes a fully winged adult.

To give you some idea of scale, here's a picture of a freshly moulted one on a corner of an oak leaf... do leaves have corners?


After keeping these just long enough to observe the first moult and then make sure they were all in good health for a few days, I released them and they seem to be doing just fine in my garden.

I'll be back soon with yet another observance first for me that I want to share.

Until the next time then...

Oh! Just before I go...the latest photograph of the poplar hawk moth caterpillar....



What a treat eh?


9 comments:

Anonymous said...

These blog entries are so fascinating and informative. Please continue to share with us and educate about the hidden world that you explore so fascinatingly.

Anonymous said...

*S*T*O*N*K*I*N*G*!!!!!!! Absolutely flippin' fantastic JJ! Something I've always really wanted to witness as well but I'm terrified of killing things!! Been watching a 'family' of Parent bugs over the last few weeks which has been fascinating as well. As for sounding crass, well heck no! It doesn't! It's a privilege to be able to see this happen and I would find it very moving too! So we can sound crass together if you like! Lol!
The caterpillar looks like he's doing well too! Found a young Elephant HM caterpillar last weekend which was nice!

Keep cool! ;-)

Maria

Anonymous said...

PS the photography here is **outstanding** too btw! Not that it isn't always...! But you know what I mean!
M

JJ said...

Hello Maria,
Thank-you for yet another (prompt) comment on my little blog entry. I have not managed to kill anything yet and would probably stop the moment I did and so, as long as nothing suffers, I find this a brilliant way of adding to my knowledge of these creatures and then to share here is another bonus. Actually, I have to be alert to the fact that they probably do better in my care than they would left to their own devices, if I release too many...

I've also been looking for parent bugs in the usual places but no sign as yet. A bit of synchronicity here because I have been searching the willow herb for elephant hawk moth larvae too :-) No luck with those either...yet!

RayHolden said...

Excellent blog entry!
Yes, Common Green Sbs do make lovely honeycomb patterns with their egg-laying. Usually though they seem to aim for a multiple of 7 eggs rather than the (3 times 9 = ) 27 you have there.

Did you ever see this : http://www.eakringbirds.com/eakringbirds5/insectsshieldbugovae.htm ?






JJ said...

Thanks for your comments Ray. I hadn't actually realised that the usual pattern of laying was multiples of seven,so thanks for that info. I hadn't seen that link you provided either. Very similar to mine here and some cracking photos to boot!

RayHolden said...

It was Ash Wood who first pointed out the "multiples of 7 " thingie to me, but although I have seen some "7x -1" eg 26 eggs , in those cases it looks like the poor thing just ran out of them - so the matrix of eggs is one short. The Southern Green Sb (which lays lots and lots of eggs in one cluster) may have a similar characteristic, but I just have enough fingers and toes to study them properly.

I did once try to record something like wot you've done here: http://flic.kr/s/aHsjtYynQq
... and suffered the same frustration with these:
http://flic.kr/s/aHsjuUyPG5

Ray






Anonymous said...

Amazing photography JJ, absolutely stunning sequence. So delicate looking freshly moulted. I so enjoy your blog. Can't wait to see your what your next one has in store for us.

Stevie

JJ said...

Awe thanks Stevie...

I will be adding an update very soon after a real shortage of time for all kinds of reasons :-)
JJ.