single horsehair worm is very thin and wirey
Horsehair worms
Order: Dioctophymoidea 
Subclass: Goriacea

a handfull of skirming horsehair wormsHere we have a handful of horsehair worms found In early February in a small puddle on Outside Creek under the weir. They do appear like living and skirming pieces of course hair or wire. As you can see their colors are from light tan to dark brown with all different sizes.

Horsehair eggs are laid in the water in long strings where the adults live.  After hatching, the larvae penetrate some aquatic insect; they escape in some unknown way from this host and find their way into a second host; usually a beetle, cricket, or grasshopper; in the body cavity of the second host the larvae continue their development eventually passing out into the water where they become mature.  Since the adults live only in water, those that survive probably emerge from terrestrial (flying) insects, which constitute their second hosts, that chance to  drown in watering troughs and small ponds.

(Many thanks to Richard Webb, member of Four Creeks Chapter, for this information on harsehair worms. He credits INVERTEBRATE ZOOLOGY by Robert W. Hegner, printed April, 1933.) 

More Links:   Ohio State University Fact Sheet

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