In the spirit of Last Days Month, I’ve decided to dust off a few old parasite posts I’ve been meaning to do. So . . .
Meet the exoparasitoids!
Um, what? Well, do you remember toxoplasma, the beastie that lives in peoples’ brains and makes them act like cats? (See chapter 5 of Peeps for details.) Toxoplasma lives its entire life inside other animals; it’s a pure parasite, in other words.
But exoparasitoids spend most of their lives as free-living animals, flying or walking or swimming around like the rest of us. But at certain stages of life, they transform into parasites, sort of like werewolves turning from human into beast. An example of this in Peeps is the screwflies of chapter 10. They are normal flies as adults, but they grow up as parasites.
A few days ago, I was checking out Carl Zimmer’s blog and came across a post about a wasp called Ampulex compressa. Ampulex lives its life like a normal wasp, until it gets ready to lay eggs, at which point it becomes a full-fledged, zombie-cockroach-driving parasite!
Warning to the squeamish: Stop reading! Flee to Kitten War right now!
So what happens is this: when Ampulex is ready to lay an egg, it stings a cockroach on its belly, temporarily paralyzing it. Then it sticks its stinger into the roach’s brain, performing a little bit of neurosurgery. When Ampulex is done, the cockroach’s willpower has been destroyed!
It’s a zombie cockroach, a slave.
Ampulex takes it by the antenna and leads it home. The roach meekly follows, allowing itself to be sealed up inside the wasp-lair.
Do you think what happens next is pleasant? Then you would be wrong. (But Kittenwar is still available.)
Ampulex lays its egg, and when the larva hatches it eats its way into the enslaved roach, feasting on its organs. After growing into a fully formed wasp, it pops out in Alien fashion, as shown in the photo above.
Was that fun? Then tune in next week for parasitic cancer!
Don’t they look pretty together?
And if you want to check out where all my parasitology is stolen from, go buy Zimmer’s book, Parasite Rex.