Currently viewing the category: "Bot Flies"
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Human Bot Fly larva pics
April 29, 2010
Hey Bug Guys! I have some pictures of the Human Bot Fly larva that I picked up in Belize. (Perhaps more literally, they picked me…). I’d be happy to send them to you if you would like (and enjoy gross pictures).

Hi Sierra,
By all means, please send them.  Please keep the subject line the same and include all relevant information.

Human Bot Fly on Host

June 4, 2010
Sorry it took me a while to get back to you.  The first picture is the back of my neck, where the larvae were growing (about 1 month after infection) and the second one is one of the larva next to a ruler (CM scale).  I had a miserable time convincing American doctors that I actually had these insects as parasites– they wanted to treat me for staph infections and paranoia.   I was only able to remove/kill them by covering their air supply in the skin with superglue left on over night.  I hope that anyone who thinks they may also have a bot fly infection finds this page and tries the superglue- nothing else I tried (suggestions from the internet of using meat or petroleum jelly) worked.
Thanks and enjoy!
Sierra Blatter

Human Bot Fly Larva

Hi Sierra,
Thanks so much for providing this wonderful account and accompanying images of an encounter with a Human Bot Fly in Central America.

What's That Bug? does not endorse extermination

December 12, 2009
A friend was cleaning a recently harvested florida whitetail deer and inside the jaws of the deer they found some kind of worms that were about the size of the first 2 joints of a females pinky finger. They were white and had pincher like things on what I’m assuming is the head end of the worm.
Central Florida

Nasal Bot Fly Maggots in a Deer

Nasal Bot Fly Maggots in a Deer

Hi Susy,
We are quite excited to get your image of Nasal Bot Fly Maggots in a Deer’s head.  According to the Missouri Department of Conservation Website:  “Nasal bot flies (Cephenemyia spp.) are common parasites that infest the nasal passages of deer. They most often are found by taxidermists while preparing heads for mounting, although hunters occasionally notice them.  Adult female flies deposit small larvae in the nostrils of the deer. The larvae enter the nasal passages and pass through several stages of development and growth. They are liberated when the deer sneezes. They then form a pupa and emerge as an adult fly.  Although quite large (up to 1 1/2 inches) and unpleasant looking in the final stages of development, nasal bots cause little harm to the deer and do not infect humans. They also do not affect meat quality.
“  According to BugGuide:  “Eggs hatch inside the female fly and the newly emerged larvae are deposited in the nostrils of a suitable host. These larvae quickly migrate through the nasal passages into the nasopharyngeal (throat) region, preferably in the throat (retropharyngeal) pouches (causing nasopharyngeal myiasis in the host), where they settle and develop. After development is complete, the mature larvae are expelled from the host and pupate in the soil. Adults emerge after 2-3 weeks; since they do not feed, their life span is short and mating quickly ensues to complete the life cycle. 2 generations have been reported from the north, with the duration of each life cycle varying with the season. The winter life cycle can take up to 6 months, while the summer life cycle, half of that time.  Remarks  Usually the larvae do not cause considerable harm to the host other than mild irritation. However in the case of heavy infestations, results can be fatal for the host (death by suffocation), and consequently for the larvae (which, since are true parasites, cannot survive without a living host). Some members of the genus (e.g. C. trompe) are pests in reindeer farms in Europe, causing significant mortality and economic loss.”

What's That Bug? does not endorse extermination

wooly bear hover fly (eristalis flavipes)?
August 20, 2009
Found at 8700′ elevation on the summit of Robinson Peak in Washington’s Pasayten Wilderness
8700′ Pasayten Wilderness WA

Woolly Bear Hover Fly

Bot Fly

Dear Tvashtar,
We looked on BugGuide, and we believe your identification of a Woolly Bear Hover Fly, Eristalis flavipes, is correct.  The species mimics Bumble Bees in appearance and behavior.

Correction by Eric Eaton
August 29, 2009
… Thanks for the prompt.  I do have a couple other corrections: …
The “woolly bear hover fly” is actually something much more uncommon:  one of the bot flies that afflicts horses or deer or sheep.  I’ll try to get my friend Jeff Boettner to investigate, as he knows that family very well.  Meanwhile, if the person wants to submit the image to Bugguide, that would be great.  There are precious few images anywhere of these insects. …

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never seen this one!
August 18, 2009
I was out shooting at Goose Lake Praire in Illinois and came across this red eyed black and grey bumble bee looking bug.Ive never seen one before …any ideas? One friend thought it was a bee fly but I cant find any photos that look like mine?! Also it looks like it maybe laying orange eggs or maybe thats part of the plant?

Bot Fly Ovipositing

Rabbit Bot Fly Ovipositing

Hi Denise,
Someone has been hard at work on BugGuide identifying all the Bot Flies in the genus Cuterebra to the species level.  We do not have the necessary skills to perform that task for you.  Bot Flies are mammalian ectoparasites and they are generally very host specific.  Once we took a better look at your photographs, we realized that you caught this female Bot Fly in the act of ovipositing, or laying eggs on the grass.  We would need to further research this, but we believe the eggs hatch and then the maggots would attach to a passing/grazing host.

Bot Fly

Rabbit Bot Fly ovipositing

Comment from Karl
I think you are right on all points Daniel, except perhaps the ectoparasite part. It does look like a Cuterebra spp. which are opertunistic parasites of small mammals. According to the online Merck Veterinary Clinic ( “Adult Cuterebra flies are large and bee-like and do not feed or bite. Females deposit eggs around the openings of animal nests, burrows, along runways of the normal hosts, or on stones or vegetation in these areas. A female fly may deposit 5-15 eggs/site and >2,000 eggs in her lifetime. Animals become infested as they pass through contaminated areas; the eggs hatch in response to heat from a nearby host. In the target host, the larvae enter the body through the mouth or nares during grooming or, less commonly, through open wounds. After penetration, the larvae migrate to various species-specific subcutaneous locations on the body, where they develop and communicate with the air through a breathing pore. After ~30 days, the larvae exit the skin, fall to the soil, and pupate.” Sounds a bit nasty!  K

Hi Denise,
This is a female botfly, Cuterebra buccata which is a rabbit bot. Its host is generally Sylvilagus floridanus (and maybe other species of Sylvilagus in some areas). The larvae are sometimes seen in the neck or shoulder, and/or rump and hip of the rabbit. The red marks in the eyes are only observed in rabbit bots, and your location in IL helps narrow it to a few species. Luckily there is just enough of the white lower face showing in your photo to narrow it to C. buccata. They are not very often seen laying eggs, so nice to catch that on film.

Comment from Eric Eaton
That is so awesome!  I know the guy who is working on Cuterebra, and I forwarded him your message.  His name is Jeff Boettner and he works in the building next door to me here at UMass.  He says that about 30% of the known bots from North America are already on Bugguide, and that the most difficult species to find are already documented, some probably imaged for the first time ever.  Keep those bots coming!

Professional Identification forwarded by Eric Eaton
Hi, Daniel:
Here is Jeff Boettner’s response….”C” is for Cuterebra, so it is Cuterebra buccata.

Thats C. buccata a rabbit bot. I sent a post but I am not in the loop with that group so may take a bit for it to be posted.

What's That Bug? does not endorse extermination

additional bot fly pics
Mon, Apr 13, 2009 at 12:02 PM
I saw that you posted some bot fly pics, but they were a little fuzzy. Here are a few I took that are a little more detailed. Perhaps not the exact same kind of bot fly, but pretty similar. There appear to be three tiny eyes between its two big compound eyes.
Northern Indiana

Bot Fly

Bot Fly

Hi Vince,
Thanks for sending us your Bot Fly images.  Now people can understand why the Interested Mountain Girl thought it looked like a mutant.

What's That Bug? does not endorse extermination

Black and White Bumblebee-Like Relative Found near Yosemite? Sat, Apr 11, 2009 at 3:12 PM
This might be some sort of mutant insect, because it certainly beats me. I found it rolling amongst the pebbles outside my mountain home near Yosemite, where many common bumblebees and honeybees flourish. Something is definitely off… Instead of mouth parts it has nostril like holes and the flesh above the undersized wings (it cannot fly) appears withdrawn, or peeled up.It’s first two segments have a white furry underbody and a shiny hard top. It’s last segment is shiny and hard. It has no antennae. It’s eyes are black with two red spots, one on the top and the other on the bottom portion. I figure mutations might not be your forte, but is this just a really weird insect? He’s also about an inch long.
Interested Mountain Girl
Coarsegold, near Yosemite Valley, CA

Rodent Bot Fly

Rabbit Bot Fly

Dear Interested Mountain Girl,
We wonder how long you are going to maintain your interest when you learn that though it looks like a Bumble Bee, this is actually a fly, a Bot Fly to be exact. We believe it is a Rodent Bot Fly. Bot Flies are endoparasites of various mammals and they cause swellings knows as warbles, giving the Bot Fly the name Warble Fly as well. Rodent Bot Flies tend to parasitize squirrels and rabbits. In Central America, there is a Human Bot Fly.

Wow, this is actually even cooler. I hadn’t realized we had those here, but I’d not paid much attention to the insect and bug life since I moved here a few years ago. Sorry for the poor picture quality, the camera wasn’t working at it’s best, but thank you for the amazing and prompt response, you guys really are amazing bug people!
Right now my little Bot buddy is in a glass jar with a damp paper towel and a few leaves, and he seems to be getting more active by the hour! I’ll free him pretty soon, and he can go back to his biting, buzzing ways, much to the chagrin of the local voles and bunnies.
-Interested Mountain Girl

What's That Bug? does not endorse extermination