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The Lynddie England of Hymenoptera

Nice, nice, nice article on cockroaches and parasitic wasps from Carl Zimmer at Corante, via Pharyngula. (There’s a movie too ).

February 02, 2006

The Wisdom of Parasites

Posted by Carl Zimmer

I collect tales of parasites the way some people collect Star Trek plates. And having filled an entire book with them, I thought I had pretty much collected the whole set. But until now I had somehow missed the gruesome glory that is a wasp named Ampulex compressa.

As an adult, Ampulex compressa seems like your normal wasp, buzzing about and mating. But things get weird when it’s time for a female to lay an egg. She finds a cockroach to make her egg’s host, and proceeds to deliver two precise stings. The first she delivers to the roach’s mid-section, causing its front legs buckle. The brief paralysis caused by the first sting gives the wasp the luxury of time to deliver a more precise sting to the head.

The wasp slips her stinger through the roach’s exoskeleton and directly into its brain. She apparently use ssensors along the sides of the stinger to guide it through the brain, a bit like a surgeon snaking his way to an appendix with a laparoscope. She continues to probe the roach’s brain until she reaches one particular spot that appears to control the escape reflex. She injects a second venom that influences these neurons in such a way that the escape reflex disappears.

From the outside, the effect is surreal. The wasp does not paralyze the cockroach. In fact, the roach is able to lift up its front legs again and walk. But now it cannot move of its own accord. The wasp takes hold of one of the roach’s antennae and leads it–in the words of Israeli scientists who study Ampulex–like a dog on a leash.

Full Article

Video

I’m very happy to have found this blog – such a wealth of stuff it’s like unexpectedly being given a luscious selection of chocolates to choose from and not knowing where to start gorging. Cheers, PZ.

Tags: Science Biology Parasites Wasps

Published by Palau

Been there, done that, bought the t-shirt, washed the t-shirt 23 times, threw the t-shirt in the ragbag, now I'm polishing furniture with it.