I have no clue what happened here

Last weekend I went with on a field trip to Guáquira Ecological Station in Yaracuy, Venezuela. During a walk to one of our field sites we passed a group of plants in the family Musaceae, and a small protrusion caught my eye. On the side of the leaf stems I saw a katydid in the subfamily Conocephalinae, tribe Copiphorini staying very still. As I got closer, I could see that it was dead. What was interesting is that it died while, apparently, laying eggs:

Laying eggs?

Laying eggs?

But there was something that didn’t quite add up. Upon closer inspection, the insect was fixed to the side of the stem only by the ovipositor, and there were no eggs to be found.

Oviposicion-02

The legs were awkwardly folded underneath, it looked faded and it was in a conspicuous position; it had many signs of having been infected with a parasitic fungus, except there were no spores, fungus body or anything that looked like fungus. Very odd indeed. Then I looked at the other side, and things got stranger:

Parasitoid exit hole

Parasitoid exit hole

That looks like a parasitoid exit hole, which makes little sense, at least from what I’ve seen in the field. I usually see these exit holes in eggs, larvae or pupae, not adults, but it’s possible. There are tangle-veined flies (Nemestrinidae) that have been reared from katydids, as well as some tachinids like Homotrixa alleni, but nemestrinids and most tachinids are larger than this exit hole. So what could this be? A random occurrence? A parasitoid that modifies the host’s behavior and makes it die while making an attempt at laying eggs? A katydid that had a parasitoid inside it and then got infected with a fungus that modified its behavior, but the parasitoid ate the katydid from the inside out before the fungus could? I have no clue; all I know is that I’ll keep my eyes open in case I see something similar next time I go! If anyone has a clue about this, I’d love to know!

 

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2 thoughts on “I have no clue what happened here

  1. There are dryinids that attack Orthoptera, right? I’ve only seen them in nymphal delphacids, but if it laid an egg the nymph it might not emerge until it was an adult. Although being an ectoparasitoid, they should leave a bigger hole than that.

    • Dryinids are endoparasitoids first, and ectoparasitoids right before pupating. I found no reference of an orthopteran host (just Cicadomorpha, Fulgoromorpha and kin), but a dryinid seems unlikely. I’ve seen them on leafhoppers and delphacids, but this katydid was roughly 8 cm long, much too big for a dryinid to parasite.

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