Montana Public Radio

Bug Bytes: Voodoo Wasp

Jun 16, 2020

The more you learn about the insect world, you realize that the act of parasitism – where one species lives off of and feeds upon another species – is surprisingly common. This is especially true among wasps.

And while the act of parasitism may seem a bit gory, the details can be incredibly fascinating. In the case of a wasp commonly called the Voodoo wasp, it takes parasitism to an entirely new level by also controlling its victim’s behavior.

Many species of parasitic wasps choose caterpillars as their host species. A female wasp will infect a caterpillar with a number of eggs that will eventually emerge, grow inside, and slowly consume the host…alive. Once fully grown, the larvae will either pupate within or emerge from the caterpillar. With most examples of parasitism, this ends the host’s unfortunate life.

In the case of the Voodoo wasp, the story begins much the same, but takes an interesting turn. The female Voodoo wasp will infect a caterpillar with up to 80 eggs. When the eggs hatch, the Voodoo larvae will slowly begin consuming the caterpillar’s insides, causing the caterpillar to stop eating and moving, but keeping it very much alive.

A moth caterpillar with pupae of the Braconid parasitoid wasp Glyptapanteles sp., more commonly known as the Voodoo wasp.
Credit Professor José Lino-Neto / https://en.wikipedia.org/wiki/Glyptapanteles#/media/File:Glyptapanteles.png

Once fully grown, the larvae will emerge from the caterpillar to form a mass of pupal cases on a leaf or branch. But instead of bringing the caterpillar’s life to an end, in a bizarre twist the caterpillar becomes a bodyguard, protecting the developing wasps by violently swinging its head to chase away potential predators.

After the adult wasps emerge from their guarded cocoons, the caterpillar’s job is finally done. It soon dies…having fulfilled its Voodoo driven duties.