Sluggin' Along: Caterpillar Parasitized by Chalcid Wasp

Sunday, July 7, 2013

Caterpillar Parasitized by Chalcid Wasp

This green caterpillar is carrying the larvae of a Chalcid Wasp (Euplectrus sp.) on its back. Because the wasp larvae feed on the host from outside, they are called ectoparasites. They inject venom into the caterpillar which prevents it from molting into the next instar. They consume much of its body and nearly double in size before spinning their cocoons (which occurs about 2 weeks after they hatch from the eggs). The caterpillar will die during the migration of the larvae. From the black patch on the left side of the caterpillar, it's clear that the venom is doing its work. Also, if you look closely, you can see that the larvae have eaten chunks of the caterpillar's back.