Tuesday, January 10, 2006
Ahh, another parasitic insect that does a really remarkable, yet freaky, thing to its host. A while back I posted a note about Phorid Flies. They were the insect that laid its eggs in the head of an ant. Then, as the larva matured, they fed on the ants brains and when they got too big the ants head would pop off and the adult fly would emerge (read full note here). Anyway, this is just as weird and gross so read on.The Horsehair Worm (or Nematomorph Hairworms) enters its host (usually a grasshopper or cricket) while it is in it's juvenile stage of development. The juvenile worms are so minute that the host actually swallows the bug while drinking without knowing it. The worm then lives in the host till adulthood. This in itself is already kind of weird and gross but that's not the really strange thing. The worm actually begins to control the host by manipulating its nervous system. The worm also grows so large (in comparison to its hosts body) that it removes, or at least disables, the hosts reproductive system to make room for itself. Anyway, there isn't a lot of information on what exactly the worm forces the host to do. Not until the end at least. When the worm is ready to emerge from the host as an adult it will fool the host into jumping into a body of water. This is where the adult worms go to breed and lay their eggs. The host however usually drowns. Once the adult worms lay their eggs the process begins all over again. Sick.
For more information check out these two sites.
1. New Scientist (above picture is taken from this site)
2. University of Florida, IFAS Extension