Chordodes Formosanus

Chordodes formosanus is a parasitic horsehair worm species that primarily targets mantises as its definitive host.

Biologically, it belongs to the phylum Nematomorpha and exhibits an extraordinary life cycle involving behavioral manipulation.

After the worm matures inside the mantis's body cavity, it induces the host to seek out and enter water—a fatal behavior for the insect—so the worm can emerge and reproduce in an aquatic environment.

This manipulation is thought to involve neuromodulatory compounds or physical interaction with the host’s central nervous system.

The adult worm can reach lengths of 20–30 cm while being only 1–2 mm thick, and despite its size, causes surprisingly little tissue damage while developing inside the host.