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.
The zombie roach crawls where its master leads, which turns out to be the wasp's burrow. The roach creeps obediently into the burrow and sits there quietly, while the wasp plugs up the burrow with pebbles. Now the wasp turns to the roach once more and lays an egg on its underside. The roach does not resist. The egg hatches, and the larva chews a hole in the side of the roach. In it goes.
The larva grows inside the roach, devouring the organs of its host, for about eight days. It is then ready to weave itself a cocoon--which it makes within the roach as well. After four more weeks, the wasp grows to an adult. It breaks out of its cocoon, and out of the roach as well. Seeing a full-grown wasp crawl out of a roach suddenly makes those Alien movies look pretty derivative.
I find this wasp fascinating for a lot of reasons. For one thing, it represents an evolutionary transition. Over and over again, free-living organisms have become parasites, adapting to hosts with exquisite precision. If you consider a full-blown parasite, it can be hard to conceive of how it could have evolved from anything else. Ampulex offers some clues, because it exists in between the free-living and parasitic worlds.
Amuplex is not technically a parasite, but something known as an exoparasitoid. In other words, a free-living adult lays an egg outside a host, and then the larva crawls into the host. One could easily imagine the ancestors of Ampulex as wasps that laid their eggs near dead insects--as some species do today. These corpse-feeding ancestors then evolved into wasps that attacked living hosts. Likewise, it's not hard to envision an Ampulex-like wasp evolving into full-blown parasitoids that inject their eggs directly into their hosts, as many species do today.
And then there's the sting. Ampulex does not want to kill cockroaches. It doesn't even want to paralyze them the way spiders and snakes do, since it is too small to drag a big paralyzed roach into its burrow. So instead it just delicately retools the roach's neural network to take away its motivation. Its venom does more than make roaches zombies. It also alters their metabolism, so that their intake of oxygen drops by a third. The Israeli researchers found that they could also drop oxygen consumption in cockroaches by injecting paralyzing drugs or by removing the neurons that the wasps disable with their sting. But they can manage only a crude imitation; the manipulated cockroaches quickly dehydrated and were dead within six days. The
Its another milestone for Google's attempt to take over the world! First my homepage, next the internet, finally the entire world under the thumb of Google!...Or it might just be something really cool.
but how is this a hack? I mean its not something we could do ourselves at home and while its really nifty I don't see its overall usefulness to the everyday person for the cost. Wouldn't it just be cheaper to install glow in the dark plastic strips along the hallways and such? Just my $0.02.
in 2002, but if you're a fan of the Dresden Files, you know what really happened. =D http://www.jim-butcher.com/books/dresden/5/
and if you havn't read any of the series but are a fan of occult/mysteries I highly recommend it.
Slashdot Mirror
I havn't RTFM since it won't load here at work, but how in the world does something like that happen accidentally?
but what exactly does this article mean?
Not a drunk 5 year old, a drunk 20 year old. The net effect is the same however.
Its another milestone for Google's attempt to take over the world! First my homepage, next the internet, finally the entire world under the thumb of Google! ...Or it might just be something really cool.
They just stole it from Resident Evil 4! :-p
but how is this a hack? I mean its not something we could do ourselves at home and while its really nifty I don't see its overall usefulness to the everyday person for the cost. Wouldn't it just be cheaper to install glow in the dark plastic strips along the hallways and such? Just my $0.02.
in 2002, but if you're a fan of the Dresden Files, you know what really happened. =D http://www.jim-butcher.com/books/dresden/5/ and if you havn't read any of the series but are a fan of occult/mysteries I highly recommend it.
Hell yea! Yet another step closer to comercial space flight, so I can get off this god forsaken rock.
Only on /. would this get rated as informative
Pantless mondays?
think of the shuttle controls in Earth: Final Conflict when they read about the Virtual Display/Controls
Welcome our new asteroid hopping overlords.