Black mummies

19 Thursday Oct 2023

Tags

Aphelinus species, aphid, aphid mummies, aphid parasitised by wasp, British aphids, Drepanosiphum platanoidis, parasitic wasp, parasitised aphids

Unless I find something particularly noteworthy, this might be my last venture into the confusing world of aphids and their parasites, at least for the winter months. You might remember my post about Aphid mummies on 26 September. Well, the tiny creature pictured below is also an aphid mummy and, thanks to my local expert, I can identify this as a nymph of the aphid Drepanosiphum platanoidis that has been parasitised by one of the Aphelinus species of parasitic wasps. Within its now-blackened body, a wasp larva has been eating its host, will pupate and eventually emerge as an adult wasp. (Perhaps I should have saved this post until 31 October as it has something of the Halloween / zombie / walking dead feel to it.)

A parasitised aphid

19 Tuesday Sep 2023

Posted by sconzani in insects, trees

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Tags

aphid on Oak, aphid parasitised by wasp, leaf-turning, oak aphid, parasitic wasp, parasitic wasp on Oak, Praon, Praon wasp species

*** 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.

230919 tuberculatus parasitised by Praon flavinode (1)

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.

230919 tuberculatus parasitised by Praon flavinode (2)

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!