Bug Identifier
Horsehair Worm
Community identification

Horsehair Worm

Gordius spp. (or generally in the phylum Nematomorpha)

Order & Family
Order: Gordioidea, Family: Gordiidae
Size
Typically 4 to 14 inches long (10-35 cm), but extremely thin (1-3 mm in diameter).
See this bug in the Encyclopedia

Natural Habitat

Adults are free-living in freshwater environments like puddles, troughs, swimming pools, and damp soil. Larvae are internal parasites of arthropods.

Diet & Feeding

Adults do not feed; they rely on stored energy. Larvae are parasitic and absorb nutrients from their insect hosts (crickets, grasshoppers, beetles, roaches).

Behavior Patterns

They are famous for their parasitic lifecycle where the larvae develop inside a host insect. When mature, they chemically manipulate the host to seek water, where the adult worm bursts out to reproduce. They are often seen twisting into intricate knots, earning them the nickname 'Gordian worms'.

Risks & Benefits

Harmless to humans, pets, and plants. They do not bite or sting. They can be considered beneficial as they help control populations of pest insects like roaches and grasshoppers.