Doggedly searching for the crux of the biscuit.
Over at Corante, Carl Zimmer writes about Ampulex compressa, a parasitic wasp that turns cockroaches into zombie slaves.
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 uses sensors 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.
Neurosurgeon wasp then walks the roach back to its burrow, plugs up the entrance, and turns the roach into a living incubator. The roach doesn't die, but enters a state of suspended animation, consuming about 1/3 less oxygen than normal, while the wasp larvae eat it from the inside. Bizarre.
(hat tip: fiend)
TrackBackI forgot the two lessons of reading Apostropher.com.
#1. Never read Apostropher.com while eating lunch.
#2. Never, ever, under any circumstances, violate rule #1.
Intriguing and bizarre, indeed. Nauseating, oh yes.
Posted by: John Johnson at February 3, 2006 11:41 AMUrrrrrrr... *blink* Buh...
Oh my gods. Grossest. Thing. Ever.
Oh, gods. Gods almighty. I am so glad fiend does not think of me as the friend he tells these things to. Oh, Jesus H. in a frying pan. Ufffff.
Posted by: Robust McManlyPants at February 3, 2006 01:57 PMAw, come on. That ain't to different from the "Alien" films.
Posted by: Dave McLeod at February 3, 2006 09:40 PMOr, if you don't like the War on Terror angle, consider that these kinds of wasps caused some scientists to doubt the existence of God (and, by extension, "Intelligent Design"). Wretchard quotes Stephen Gay Gould:
Since a dead and decaying caterpillar will do the wasp larvae no good, it eats in a pattern that cannot help but recall, in our inappropriate anthropocentric interpretation, the ancient English penalty for treason — drawing and quartering, with its explicit object of extracting as much torment as possible by keeping the victim alive and sentient. As the king's executioner drew out and burned his client's entrails, so does the ichneumon larvae eat fat bodies and digestive organs first, keeping the caterpillar alive by preserving intact the essential heart and central nervous system. Finally, the larvae completes its work and kills its victim, leaving behind the caterpillar's empty shell. Is it any wonder that ichneumons, not snakes or lions, stood as the paramount challenge to God's benevolence during the heyday of natural theology?
So, wasps offer something for everybody.
Posted by: GaijinBiker at February 3, 2006 11:06 PMThere's a similar thing involving a parasitic worm (I think it's a worm, at least) that turns grasshoppers into zombie slaves. The larval worm chews out most of the grasshopper's internal organs, leaving parts of the nervous system and leg muscles intact. Then, apparently, the worm is able to secrete some sort of neurotransmitter or other factor that causes the grasshopper to actively seek out a body of water and throw itself in. Then, the worm emerges, swims around and lays eggs, a new grasshopper drinks some water, and the cycle begins anew.
Yay zombies!
Posted by: Kat at February 4, 2006 12:31 AMSuperb. Nothing like a brain-surgeon wasp to make you feel small. The more we know, the less we are.
Posted by: waldo at February 4, 2006 02:12 AMOne small correction to my earlier comment: the wasps made scientists doubt God's benevolence, but not necessarily his actual existence or his role in creating stuff. My bad.
Posted by: GaijinBiker at February 4, 2006 03:18 AMFor further examples of this phenomenon, may I present my relationship history...
Posted by: Mr. Sticky at February 5, 2006 11:17 PM