This little beauty captures mosquitoes and attaches it's eggs to it. The popular little mozzie then lands on people and passes on the eggs, along with any number of nasty diseases and infections.
The bot fly eggs drop off the mozzie and develop under the skin. By develop I mean hatch and a nice big fat maggot starts growing under your flesh, feeding off you.
A large welt develops on the skin where the maggot is growing and feeding, when it's ready it then erupts from your flesh and munchs off, leaving a nice wound.
Trying to remove the buggers is awkward, as it has rows of serrated barbs around it's body. The common treatment is to cover the welt it's caused in vasaline. The little rascals can't breath and after a day or two they joss it and can then be pulled out without causing any infection. Apparently they start writhing about when they realise their oxygen supply has been cut off, tasty.
Here's a picture of some poor bugger with one in their eye.
Happy holidaying in Mexico.
Maggot Therapy
Guinea Worm
The tapeworm diet (with picture goodness)
Elephantiasis