Bot Fly Larvae: The Deadly Parasites That Live in Your Skin

It’s summer time and very hot and humid. Mosquitoes are everywhere, and there isn’t enough spray to keep them at bay. One lands on your skin and bites you before you can smack it to death. Did you know where that mosquito had been before it landed on your skin and bit you? You may not want to know!

Image: Kcho

A common fly, more prevalent in Mexico and South America, uses mosquitoes to propagate its young. Resembling a bumblebee because of its size and hairy tufts, the botfly highjacks a mosquito in mid-flight without interrupting its flight. While still flying, the botfly glues its eggs (typically 30 of them) onto the mosquito’s body. When the mosquito eventually lands on a person or another animal, the body heat melts the glue around the eggs.

As the mosquito, unaware of the “parcel package” it’s carrying, begins to suck the blood from its host, the eggs crawl into the host’s body. The mosquito is the only way to deliver the “goods” to the host, because the botfly is too big and noticeable to the host to be able to deliver its young to the host itself.


Image: norrisiv

For six weeks the worms grow and feast upon the host, whether it’s a human or another animal. The injury occurs when the animal or human notices the bump from the growing worm underneath their skin.

Removing the botfly larvae is painful and difficult. The worm just doesn’t want to leave! The hard tufts on the backs of the maggots make it impossible for the host to remove them without surgical procedures.


However, without the removal, the host can become very sick with infection. Surgery is the best method, as even a tiny fragment of the maggot can and will create a nastier infection. The whole maggot must be removed, a procedure which can’t be insured without licensed medical care.

Before the removal of the botfly larvae, the host must suffocate the larvae by putting nail polish, Vaseline or a Band-Aid over the hole in the skin (through which the larvae breathe and excrete wastes). The larvae breathe through their butts.

Image: Joel Mills

If the host does not detect that botfly larvae is growing inside of them, after a couple of weeks the larvae will eat through soft tissue and make their way to muscle tissue.

Eventually the botfly larvae will get too big to grow under the host’s skin. They will eat their way out of the flesh of the host and fall onto the ground. The wings dry and they take flight soon after. It takes 20 days for them to become mature and be able to reproduce their own larvae and repeat the cycle.

Some larvae manage to be implanted in the host’s head. This can easily cause meningitis and death.