Today’s Factismal: May is National Zombie Awareness Month..
If you think that zombies are just found in the movies, then think again. There are real live zombies out there, and they may be in your neighborhood. But what is a zombie, really? And how did it get that way?
Put simply, to a biologist a zombie is any animal that no longer acts under its own control but is instead controlled by a parasite. The best known example of this in the animal kingdom is the poor leafcutter ant. In forests across Brazil, Thailand, and Africa, leafcutter ants are regularly attacked by a fungus known as Ophiocordyceps unilateralis (“Single fruiting body poking out of the head”, which describes how it reproduces). This disease primarily preys on leafcutter ants that make their homes in masses of bound together leaves, far above the ground.
As soon as an ant has this disease, it begins to twitch and thrash until it either falls out of the nest or is thrown by colony members who don’t want to catch it themselves. The infected ant finds a leaf, grabs on with its mandibles, and has its brain eaten by the fungus. As soon as the fungus has nibbled all of the goodies to be found in this ant, it then cracks open the ant’s head and grows a stalk with a fruiting body on the tip. The fruiting body releases spores and the whole cycle starts all over again.
And it isn’t just funguses that can cause this behavior. There are bacteria, wasps, and even flies that do this. Most ominous of those is the fly Apocephalus borealis, which turns honeybees into zombies. This “scuttle fly” is much smaller than a honeybee, but is capable of infecting dozens of honeybees with its eggs. The eggs hatch into larvae that then eat their way to the bee’s brain and drive it insane. (Bwah-hah-hah!) The bee then does stupid things, like flying at night or in the rain, which spreads the larvae further than they could go on their own. The larvae finally finish off the bee and eat their way out of the poor dead bee.
This is a severe problem for people because we rely on honeybees to fertilize many of the crops that we eat. Without honeybees, we’d be very hungry indeed. If you’d like to help spot zombees and track the spread of the zombee apocalypse, then join the ZombeeWatch: