The problem is, the pairing of this particular image with this particular caption has lead to some confusion.

While the species identities are correct, and the stated relationship between the two is correct, the caption seems to imply that the skin of the poor beetle larva is stretched shiny-tight and close to bursting from a insanely huge parasite load (indeed, this is how the interwebz has been interpreting it).

This interpretation is only a little bit correct.

The beetle IS parasitized – by one parasite. Just one.

The rest of that squirmy-looking mass on the back of the beetle is a perfectly normal thing (well, if you’re a leaf beetle anyways): it’s a fecal shield. Yes, fecal shield. As in, “poop”.

Many, many Chrysomelids (leaf beetles) create fecal shields, depositing their feces on their backs. It’s so prevalent, in fact, that the study of fecal shields warrants its own term, apparently. From the section in Caroline Chaboo’s book chapter on Chrysomelid defences entitled, “Fececology” (ha!):

Epic Moment: Shart Storm

New companion:  Mr. Hankey, the Christmas Poo!