Aphid from space

Lord V · #1 (**permalink**) 20-08-2007, 05:32 PM

Can anyone confirm this is the result of parasitism by an Ichneumon wasp. Have to admit when I first saw one of these last year I thought it was a fungal infection.

Brian V.

jdoherty · #2 (**permalink**) 20-08-2007, 10:41 PM

Haven't a clue what it is but I think it looks great.

John

Lord V · #3 (**permalink**) 21-08-2007, 08:03 AM

Quote:

Originally Posted by jdoherty

Haven't a clue what it is but I think it looks great.

John

Thanks John

. I've seen these before and the disc is always perfectly centred around the centre of the aphid's abdomen.
Brian V.

bugbotherer · #4 (**permalink**) 21-08-2007, 08:33 AM

Fascinating, I've never seen that before.

brucemstrs · #5 (**permalink**) 21-08-2007, 09:04 AM

I am totally mystified - can anyone tell me as well what it is ???

Dogghound · #6 (**permalink**) 21-08-2007, 11:01 AM

Im not sure if its the work of a ichneumon, parasitic wasps such as Aphidius matricariae & Aphidius colemani attack aphids in a different way to this, the egg is laid in the aphid, then it eats the aphids inside body tissue, then it spins a cocoon inside the aphid, the aphid swells and hardens, then it emerges, im unsure as to how this disk would form in this process, although there are several aphid parasites. Some Ichneumons attatch the aphid to the plant, which could possibly be what this is species such as Aphidius eadyi are know for this.

Lord V · #7 (**permalink**) 21-08-2007, 12:13 PM

Thanks for the comments and suggestions so far

. Whenever I have found these they have been totally isolated from any other aphids- one of them was on a fence post.
Brian V.

Dogghound · #8 (**permalink**) 21-08-2007, 01:28 PM

Hm iv just noticed the heavily swollen abdomen on the top photo, makes me think more likely a parasitic wasp. Aphidius sp

Venger · #9 (**permalink**) 21-08-2007, 06:33 PM

For a moment I thought you'd stuck it to a penny.

wyevilla · #10 (**permalink**) 21-08-2007, 08:06 PM

LordV

We had an aphid similarly affected last year. The thing is it was stuck to a window. enabling you to see underneath the disk. Inside was a very small, segmented larva. which I took to be a parasitic wasp. Unfortunately, pupaption and emergence of the adult took place whilst we were away.

I wonder if the aphid seeks to distance itself from others of its species when it has been infected. This could be an adaptive behaviour to reduce the spread of the the parasite which would eexplain the isolated nature of your and my sightings.