Five years ago I wrote about the discovery of a little wasp in Mexico and Brazil that apparently spins silk over stink bug eggs after inserting its own eggs in them. A few days later I made a follow-up post with a few more photos from Brazil, reporting that Mike Gates had identified the wasp as a Neorileya species (Eurytomidae—in the first post it was misidentified as a pteromalid). He had never heard of Neorileya producing silk, and was interested in more concrete proof that this wasp was actually responsible for the silk.
Well, this week Kel Silva, who sent me the previous photos from Brazil, passed along a couple of videos of one of these wasps, taken by her friend Giovane Proença:
Seems pretty conclusive to me. Here’s a photo Giovane took of the scene with an American quarter for scale:
And a photo of another silk-covered stink bug egg mass from Brazil, this one taken by Jhonatan Santos:
As far as I know, no one has yet collected one of these wasps, so their exact identity is still unknown, if they in fact belong to a species that has been given a name. The function of the silk is presumably to make it harder for other wasps to lay eggs in the parasitized stink bug eggs, thus parasitizing the parasitoids.