Horsehair Worm

Horsehair worm, known as Gordian worms, belong to the group Nematomorpha - similar to nematodes but much longer and thinner. They ranging in size from, in most types, of 50-100 cm (20-39 in) long and can reach in extreme cases by up to 2 meters, and 1 to 3 millimeters (0.039 to 0.12 in) diameter. Horsehair worms evolve as parasites in the bodies of of locusts, crickets, roaches, and some insects. When mature, they go host to pass the eggs. These interesting creatures are parasites of humans, livestock or pets and pose no threat to public healthcare.Nematomorphs can be confused with nematodes, particularly mermithid worms. Unlike nematomorphs, mermithids do not have a terminal cloaca. Also, horsehair worms resemble hairs from horses actively moving in the water. A superstition held that the worms in water troughs and puddles had miraculously come to life from the long, thin hairs of a horse's tail that had fallen into the water.

Horsehair worm in a grown up state

HORSEHAIR WORM LIFE CYCLE

Horsehair worm adults mate in the water, usually in spring, where after that the females lay long strings of eggs (with the internal fertilization). Males coil around females in pools of fresh water or damp soil. It is not uncommon for a number of individuals to be intertwined, forming a loose ball during mating. The life of the microscopic larvae is not completely understood. Depending on water temperature, the eggs hatch in two weeks to three months. Within 24 hours after hatching, it is thought to form a protective covering or cyst. If the cyst is eaten by a suitable insect ,locusts, crickets, roaches, or other, the protective covering dissolves and the released larva bores through the gut wall and into the body cavity of the host. Once inside the host, the larvae live inside the haemocoel and absorb nutrients directly through their skin. Development into the adult form takes weeks or months. 

Horsehair Worm - photo by. http://biodidac.bio.uottawa.ca

After that, ususally, is the host dead or near the death and then the worm leaves it.. How and why? Well... While they parasite their host, they store up fats and food reserves. When the horsehair worm is mature and near water or damp soil, it emerges from its host. Once emerged, adults are free-living and do not feed. Here is an example video (NOTE: DON'T WATCH IT IF YOU HAVE A BAD TASTE FOR WORMS)

As you can see, the infection acts on the insect's brain and causes it to seek water and to drown itself, returning the horsehair worm back to the water, so that it can help lay the eggs and die...

 

HORSEHAIR WORM ARE HARMLESS TO PEOPLE

Horsehair worms are harmless to people, pets, and plants. In fact, they can be effective in controlling certain insects. Horsehair worms are nothing more than a curiosity. No control is necessary. If they want to be observed, they can be found during late summer or fall in streams and ponds, but are more commonly noticed in domestic water containers such as bird baths, swimming pools, water troughs, pet dishes, sinks, bathtubs and toilets. If you ever found one, have fun observing the Horsehair worm.

Horse hair worm is an article published on the blog Horsehairworm.blogspot.com