The Torsalo Fly

Torsalo Fly (Dermatobia hominis)

Just to torture you a little more...This fly does much worse than land in your potato salad.

Since so many of you clicked out to view the link that I warned you against, I thought I would give just a little more information. This is from The Diptera Site:

Dermatobia hominis, also known as the Human Bot Fly, the American Warble Fly, and Torsalo is a Neotropical species which employs an extraordinary mechanism to parasitize its vertebrate hosts. D. hominis is endemic to the region extending from south of Mexico to northern Argentina and Chile. Adults range in size from 10-15 mm; are metallic, bluish-black in body color; have brown wings; and display yellow markings on the face and legs (Linnaeus Jr.’s original description). A rather conspicuous fly, given its size and coloration, this obligate parasite uses a process called phoresis (to carry or wear) in which another fly species becomes a vector for the transfer of D. hominis larvae to a suitable host. More specifically, following copulation a bot fly female will capture a mosquito, or in most cases some other hematophagous (blood-feeding) fly, in mid air where she proceeds to glue 10-50 eggs to its abdomen. These temperature-sensitive eggs develop and hatch in response to heat from the vertebrate host on which the vector feeds or lands.... (and then comes the really bad part)

And then if you still haven't had enough − (I'm feeling really evil today, heh, heh) − there is the gruesome video recommended by Aaron (Pensieve blog) in the comments to my last article on this topic, Invasion of the body snatchers..... The Diptera Site includes a distribution map of the fly and it looks to me like it is headed your way.

Sleep well, everyone!


I really felt that this article would have been enhanced with some creepy horror movie music, but I don't much like sites that play music so I didn't bother to try to figure out how to do that.