Image By Doc. RNDr. Josef Reischig, CSc. / CC BY-SA 3.0

A Bug That Lives in Other Bugs

The Strepsiptera is one of the creepiest, most unnerving bugs we have ever discussed in this blog. What makes it so creepy is that they are born, and even live inside of other bugs, such as wasps, bees, and cockroaches. Adult male Strepsipteras do not live very long at all. Most of the time they do not live for more than 5 hours, and don't even feed during that time frame. On the other hand, females live for a lot longer, but they actually live inside of the insect they are born in! The Strepsiptera females, living inside of the abdomen of a wasp or bee, release a hormone, which the males use to locate them. Very painfully to the host, the Strepsiptera female pokes its anterior region out of the body of the host, breaking the skin and causing extreme pain to the host insect. The males, having been attracted by the hormone from the females, find the females anterior sticking out of the hosts body, and then mate with it. Once this process is complete the male has no other purpose and he dies quickly. However, the female still has a job to do. The female becomes pregnant with not just a few larvae, but literally thousands of minuscule larvae with legs. These larvae then eat their mother from the inside! Child birth is painful enough, but imagine being eaten alive from the insides of your stomach by thousands of small larvae! Throughout this whole process, the host insect remains alive, and in pain, as well surprisingly. Once the larvae have eaten their way out of their mother, they still have to get out of the original host insect. They begin making their way to the head. Once they get to the hear, they push and eat their way out of the head of the host insect, thus killing it as well. Once they have eaten their way out of both their mother, and the original host, they go on looking for a new host to begin their life in. Once they find a new host they find a way into its body, many times finding a small hole or scratch in the insects skin they can exploit. Once inside of the new host they no longer have a need for their legs, so they go through a process called hypermetamorphosis, which turns them into a legless version of themselves. They then trick the host insects body into making a mag-like structure inside of its abdomen that feeds the Strepsiptera and also even protects it from immune deficiencies of the host. If the larvae is a male, once it is fully grown inside of the host, it will then grow a pair of wings and break out of the host. Then its only purpose is to find a female to reproduce with, and the cycle begins all over again.

Image of the Strepsiptera's abdomen sticking out of a host abdomen | Image By  maxson.erin  \  CC BY 2.0

Image of the Strepsiptera's abdomen sticking out of a host abdomen | Image By maxson.erin \ CC BY 2.0

Adult male Strepsiptera have eyes unlike any other insect in the world. Instead of compound eyes like the flies we discussed in a previous blog, their eyes are made up of a few dozen "eyelets" that each produce a complete image individually. This means that they see the same whole entire image 12 times over, giving them an extreme ability to analyze whatever they are looking at. 

This is definitely the creepiest bug we have discussed so far, and it looks like it is going to remain that way. Not only does it live inside of another bug, but it then busts out of it and kills it! This sounds like something a monster from a horror movie would be based on. Thankfully these small creatures only use bugs as their hosts, so lets hope that as time goes on they don't develop a taste for the insides of humans for to live in!