I haven’t looked at these images in a long time. These are pictures of Exallonyx, staphylinid parasitizing Proctotrupidae wasps. I was into trying to rearing these out in college. I would find them by collecting third and final instar larvae in the spring and rearing them out to see if I got any wasps. You’ll see from the images bellow, but the number of individuals are host size dependent, and emerge in a characteristic manner.
I’ve reared three species out on various occasions from 2007-2008 which I’ve uploaded bellow. The first two species emerged from Philonthus larvae and the third from a Platydracus (I’m guessing violaceous since I found it under bark).
Philonthus pre-pupa in its chamber found under bark in early spring.
An Exallonyx larva emerges from the Philonthus pre-pupa.
Exallonyx ready to emerge.
Exallonyx sp. 1
Collected 3 individuals from their own subcorticular Philonthus during a field trip to McLean Bogs for a class on insect larvae.
Another Philonthus parasitizing Exallonyx sp. larva, exiting its host.
Exallonyx sp. 2 pupates, leaving the Philonthus larva a husk.
Exallonyx sp. 2 pupa begins to darken.
Exallonyx sp. 2
A second species of Exallonyx from another Philonthus at Six Mile Creek, Ithaca, my old hunting ground.
A closeup of Exallonyx sp. 3 reveals the larva’s minute mandibles and a vague eye spot.
All in a row, Exallonyx sp. 3 pupae.
Exallonyx sp. 3
I think this is Platydracus violaceous, the larva was under bark at Six Mile Creek. Unlike Philonthus, this large larva can house multiple individuals of Exallonyx. The larvae all emerge synchronously and orient themselves in the same manner, most notable once they have pupated.
In 2007, I was also able to rear out a Brachonidae from Sepedophilous to pupation, but the adult never successfully emerged. This was unfortunate, since this would have been the first documentation of Brachonidae parasitizing a staphylinid.