Everyone Loves Bot Flies

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Natalie McNear
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Everyone Loves Bot Flies

Post by Natalie McNear »

Bot flies are those big, loud-buzzing guys whose maggots burrow into the living flesh of mammals and feed on their host for a few months before climbing out and pupating in the soil. Luckily each species is highly host-specific, and the one species that routinely uses humans as a host is found only in the neotropics. While the larvae are serious business, the adults are about as innocuous as insects come - they are fuzzy, can't sting, and can't even bite because they have no mouthparts. The adults are incapable of feeding, and only live long enough to mate and lay eggs, and that combined with the fact that they are extremely fast fliers means they are difficult to come by.

I was lucky enough to find a deer bot fly (Cephenemyia sp.) near my house today, I think one that just emerged from its pupa in the ground because it couldn't fly very well for a while but was not worn at all. Good photo op! I tried to get a good shot that shows the lack of mouthparts, because it looks pretty weird. Many species in this genus are bumblebee mimics.

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Antonsrkn
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Re: Everyone Loves Bot Flies

Post by Antonsrkn »

Oh god, bot flies are my kryptonite. I can handle just about anything else but the very thought of bot fly maggots makes my skin crawl. Cool shots, I would never have recognized it for what it is if you hadn't mentioned it. Me being disgusted with them doesn't prevent me from admitting that they are pretty interesting, like you mentioned their host specificity is curious to me for example there is a species that only affects howler monkeys and it makes me wonder why only them and not the other primates in the area like capuchins and spider monkeys.
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Crazins
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Re: Everyone Loves Bot Flies

Post by Crazins »

Great shots! Was it in Kate Jackson's "Mean and Lowly Things" where she described bot flies in the Congo or was that a different human-burrowing maggot?

-M
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Natalie McNear
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Re: Everyone Loves Bot Flies

Post by Natalie McNear »

Thanks!

Oh there are all sorts of maggots that burrow into living flesh, the bot flies (Oestridae) are just one group and probably the least offensive of them, if that's possible. Bot fly maggots stay in one place and produce antibiotic and antifungal secretions that prevent secondary infection, so the host is relatively unharmed by the maggot with exception of the wound itself (which heals after the maggot leaves). Unless you have a large number of maggots in a small animal like a rodent, it generally doesn't cause the host much trouble. Two other families, the flesh flies (Sarcophagidae) and blow flies (Calliphoridae), also contain a lot of parasitic species, which tend to be nastier than the bot flies. In the latter two families, there are usually large numbers of maggots involved in the infestation, which burrow deep into the host's tissue and cause infection or death... Since the maggots also feed on dead flesh, the health of the host isn't really a concern to them. I think all three families are present in Africa, so it probably could have been any of them. Not sure how many species use humans as a host, though.

TMI? :lol:

EDIT: Just found this... Congo Floor Maggot. Interesting stuff!
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BillMcGighan
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Re: Everyone Loves Bot Flies

Post by BillMcGighan »

This is great.
I'm not sure I've ever seen the adult fly!!!
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Redundantly let me put this up again from the original post.
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A squirrel with wolves...
Meaning, a squirrel with an infestation of "Wolfworms", a large, fat Botfly (Cuterebra) larva that we see regularly in the SE in rabbits and squirrels.
Most squirrels I've seen on my porch with wolves, recover nicely when the worms crawl out in the fall to pupate. They seem to heal in a few weeks.
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Cole Grover
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Re: Everyone Loves Bot Flies

Post by Cole Grover »

Ha ha ha ha ha! So gross... I'm with Anton on this one - those things make my skin crawl. Literally, I guesss.

Bill, I actually feel bad for that squirrel. That's got to be a rough summer.

-Cole
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Natalie McNear
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Re: Everyone Loves Bot Flies

Post by Natalie McNear »

Awesome photo, Bill! The animals do tend to recover pretty quickly after the maggots leave their burrows. I've never seen any squirrels around here with big warbles like that... I think most of the Cuterebra species around here specialize on wood rats, and they aren't too common. So far I've only seen one rodent bot fly (and fly in the first photos is only my second deer bot fly), which was identified as C. tenebrosa. Interesting how they are much larger than the deer bot flies but parasitize much smaller hosts!

(These were taken with my old camera and before I knew the refrigerator trick to photograph insects)

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Cole - The squirrels usually do OK, it's the smaller rodents like rats and mice that have a tough time with heavy infestations. There are some pretty nasty images on Google. :?
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