How worms trick grasshoppers into leaping to their doom

This parasite makes grasshoppers jump off cliffs. Seriously, it's wild

By Smartasaurus· 1 min read Curious

A grasshopper walks calmly to the edge of a pond

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The short version

This parasite makes grasshoppers jump off cliffs. Seriously, it's wild
Once in the pond, the worm reproduces, the eggs hatch into microscopic larvae, and the larvae are eaten by mosquito larvae.
And somewhere right now, an insect is taking a walk it doesn't understand.

A grasshopper walks calmly to the edge of a pond, hesitates for a second, and jumps in. It can't swim. It drowns within minutes. As its body sinks, a thin brown worm — longer than the grasshopper itself — uncoils out of the back end and swims away.

The worm is a horsehair worm, Spinochordodes tellinii, and it has been living inside the grasshopper's body cavity, eating it slowly from the inside, for most of the insect's adult life. To complete its life cycle it needs water. The grasshopper doesn't. So the worm makes the grasshopper want water.

Researchers in France isolated the proteins the worm releases just before its exit. The chemicals mimic insect neurotransmitters and act directly on the grasshopper's central nervous system, specifically the parts that respond to light reflecting off water. The infected insect doesn't feel possessed. It just suddenly, urgently, finds water beautiful.

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