*** This post has been edited to correct previously wrong information. ***

I’ve seen these odd sights previously but only recently learned what they were and have been searching for an example to show you since then. Finally, during last Friday’s walk, with a little Oak-leaf-turning, I found another. Unfortunately the light wasn’t great so my photos aren’t as crisp as I would’ve liked but hopefully you’ll get the idea.

The creature is an aphid, most likely a Common oak aphid (Tuberculatus annulatus), but my poor photos mean I can’t be sure of that. The aphid has been parasitised by a tiny wasp that has laid its egg inside the aphid’s body. When it hatches, the larva cuts a hole in the aphid’s body and spins silk to attach itself and its host to the leaf. Then, once it has sucked the life out of the aphid and grown sufficiently, the wasp larva builds its cocoon beneath the aphid – I guess the aphid’s body acts as camouflage and protection for the wasp pupa.

The Praon genus of parasitic wasps are the only ones that create this puff-pastry-like attachment beneath their host, and, according to a local expert I’ve consulted, this is likely to be the species Praon flavinode, which is known to parasitise aphids on Oak and Birch. I’ve a mind to try to find another of these and, if the adult wasp hasn’t emerged, bring it home, put it in a jar and wait to see what emerges. Watch this space!