Once mature, S. tellinii needs to return to water to complete its life cycle. To do this, the Gordian worm infects the cricket’s mind, and forces it to commit suicide. Little is known about how the worm achieves this, but French scientists recently reported that the expression of certain proteins in the infected cricket’s brain were altered, namely those involved in neurotransmitter function and geotactic behaviour. The partly-digested and now zombified cricket seeks out water, and once there, throws itself in, and drowns. The adult Gordian worm then burrows out of the cricket carcass, swimming away to find a mate. So uninterested is the Gordian worm in the non-parasitic stage of its life cycle that it doesn’t even have a mouth - it will live on the reserves built up whilst inside the host and then die. Each female Gordian worm can lay up to 10 million eggs. Bad news for crickets, good news for zombie fans.
Here is a video that is making it's way through the intertubes, of the suicide and emergence from the cricket of this creepy parasite.