Horsehair Worms: the Nightmare You Didn't Know You Had

I know, pretty gross - right? I was doing a little bit of research on parasites for something I am writing when I stumbled across these little fellas.

These.. "hairy" little nightmares are called Horsehair Worms (more formally known as Nematomorpha). This one in particular has taken up residence inside of a cricket. They're a parasite that can range in size from 50 to 100 millimetres. In really extreme cases, they have been found to be able to reach up to 2 meters!

The more you read about them the more creepy and disgusting they become.

They're generally found in damp locations (puddles, swimming pools, watering troughs). So, basically anywhere you can sip or dip, they could be a-waiting!

There are four stages to their gross little life cycles..

While there are variations of their life cycles, it usually goes like this..

Once the larva hatches, it is consumed by an aquatic insect (a mayfly nymph). While it is inside, it encysts and it doesn't actually begin to develop until it is eaten by a host (a grasshopper, for example). Then, it parasitizes! Once it's all up inside of the grasshopper, it grows into an adult and makes it's emergence when the grasshopper finds water.

If the grasshopper doesn't make it's way to water on it's own, that's a-okay! They're able to use neurotransmitters to make the host hopper jump into the next available body of water, where they are free to carry on their reign of terror.

I was fascinated to find out that an insect can actually survive an encounter with these parasites.

I would like to tell you that you can rest easy, and that they've never had any recorded human hosts.. but they have! Several cases have been recorded in Japan as well as China.

Sleep tight.