Feb 232013

When I woke up Wednesday morning, I never could have guessed that I’d stumble across the most bizarre and terrifying fly-related idea I’d ever heard later that day. But then again, the internet is a weird and wacky place, so perhaps I should have known better.

While innocently looking for scanning electron micrographs of bot fly larvae (Diptera: Oestridae), I chanced upon Insecti-cure, a website promoting, among other things, a “treatment” for fat removal involving intentional bot fly infestations. Really.

Bot fly larvae are THE safest way for fat to be removed.

the maggots are planted next to the stomach, and will eat around the organs, the treatment, is of course painless, after you have had your injection of morphine and you will only be there for 8hrs, you will be subject to 300 larvae which have antiseptic saliva, to literaly eat the fat away, before this operation you wil need to contact us 3 weeks before in order for us to get our orders ready and don’t worry after the morphine you wont be able to remember anything, even if you are squeemish!


I couldn’t make this crap up if I tried.

 Let’s break this hot, maggoty mess down:

  1. Bot fly larvae ARE NOT the “safest way for fat to be removed”. That distinction goes to a healthy diet and proper exercise, end of story.
  2. Bot fly maggots can not be planted “next to the stomach”. The human bot fly (Dermatobia hominis) is an external parasite which burrows into the skin from the outside after a wickedly cool & complicated life history (more on that in a moment) and “only” burrows about an inch into your body eventually. If they’re using bot flies of the Gasterophilinae, which, as their subfamily name suggests, develop in the digestive tract of their hosts (horses & deer are the best known victims, but there are bot flies which specialize in the guts of elephant or rhinos — yes, bot flies really are that awesome), then they feed on the interior walls of the stomach or intestines, not “around the organs”. Also, you’d have to eat bot fly eggs. Ew.
  3. The “treatment” will not be painless, and will definitely last for more than 8 hours. Assuming they use Dermatobia hominis, one researcher who allowed his new friends to develop to term noted periodic itching during the 2nd week, and “excruciating pain” by the end of the 3rd week, which presumably continued until the maggots exited his body to pupate after a total of 47-51 days (Dunn, 1930). Yes, it takes nearly 2 months for human bot flies to develop, significantly more than the 8 hours advertised. As for gut bot flies, they can cause gastrointestinal ulcers, so yeah, there will be pain.
  4. 300 larvae?! Are you kidding me? Sure, you might lose a few ounces of tissue (not necessarily fat), but you’ll have an incredibly high risk of secondary infection and the pain & irritation would likely be overwhelming, not to mention the Swiss cheese scars around your midriff will look atrocious at the beach! Oh, and did I mention you’d likely have to endure dozens of mosquito bites in the process? Dermatobia hominis has one of the most fascinating life histories of all insects: after mating, female bot flies catch female mosquitoes alive (or a number of other insect vectors like muscids or even ticks), lay up to 30 eggs on each mosquito, and then let them go to serve as a personal delivery service. The eggs take about a week to mature, and then hatch when they sense an increase in ambient temperature when the mosquito lands on you to suck your blood. The bot fly maggots crawl off the mosquito and onto you, and proceed to burrow into your skin to begin feeding. I can only imagine how complicated Insecti-cure’s bot fly rearing facility would be, which probably explains why they need 3 weeks to prepare…

I think it’s pretty obvious that bot flies aren’t a viable strategy for getting rid of unwanted fat, and the Insecti-cure site is likely some sort of spoof (Jules Bristow emailed them pretending to be interested in their treatment, but her email was bounced back to her apparently). But, that doesn’t mean that someone, somewhere won’t come across the website and believe it’s real, at which point it will only be a matter of time until it’s being indiscriminately shared and “Liked” a bajillion times on Facebook. One reason why this bot fly story may be believable is the fact that there are legitimate medical uses for fly larvae, but they involve blow fly maggots (Calliphoridae) which only eat dead, necrotic tissue in open wounds which aren’t healing properly (link is to a graphic, yet informative video about maggot therapy – be warned), and are certainly not used for cosmetic purposes. Needless to say, this true maggot fact that people might be aware of can unintentionally lend credibility to the bot fly weight-loss program. That’s why it’s important to remember: if a new weight loss strategy sounds so disturbingly gross that it can’t possibly be true, thankfully, it more than likely isn’t.


If you’re interested in learning more about the awesomeness that are bot flies (Oestridae), I highly recommend checking out The Oestrid Flies, edited by D.D. Colwell. It’s a fantastic review of bot fly diversity and biology, including breakdowns of hosts, life histories and pathologies for the entire family, and includes plenty of photos (which I excluded here in deference to my more squeamish readers — you’re welcome).

If you want to see a bunch of biologists nerding out and drinking beer while watching someone remove large bot fly larvae from their arm, check out this awesome video and post on one of my favourite Tumblrs, Evopropinquitous (aka Things I Learned as a Field Biologist).

Finally, if you’re interested in other ridiculous insect-related remedies, check out Bug Girl’s Pinterest Board of Incredibly Bad Ideas.


Dunn L.H. (1930). Rearing the Larvæ of Dermatobia Hominis Linn., in Man, Psyche: A Journal of Entomology, 37 (4) 327-342. DOI:

  12 Responses to “No, bot flies are NOT a viable weight loss option”

Comments (10) Pingbacks (2)
  1. …the things people will do to loose weight…

  2. I hear chigoe fleas can accomplish a similar feet :)

  3. What is it with your morbid facination with maggots…..gawd…..:(

  4. I raised one of these to adulthood. I accidentally got it in Costa Rica, discovered it when I got back to the US, and wanted to see what the adult looked like. It was painful and took at least a month after I had returned.

    The crazy thing about the weight-loss story is that these fly larvae don’t eat fat at all. They suck lymph fluid. In my case, it made an egg-sized bump on my shoulder, but after the larva emerged from my body the bump completely disappeared, and there was no depression there either. The maggot would have no cosmetic effect on body shape at all. My maggot (which was ringed with small black backwards-pointing spines, in case the host stupidly tries o squeeze it out) had just separated layers of my skin and inner tissues, and was living comfortably between them, drinking lymph. After it left, my arm looked exactly like it did before my guest had arrived, except for a small hole it had made for its breathing tube and emergence route. Amazingly, it did heal instantly, so I suppose the larva secreted antibiotics.

    By the way, many biologists have raised the maggot, but most screw up after the maggot leaves the body. These maggots need to dig in order to pupate, so give it some dryish sand in a cup. Several weeks later, your “child” will emerge from underground as a fly. I was surprised that it was not much larger than a housefly even though the larva was big. It also looked a lot like a housefly, except for its prominent pinkish-orange antennae.

  5. That website is hysterical… obviously satire (tarantulas stimulating your “craniderm” nerves… there is no such thing). But it really gets at the fact that people WILL do anything if they think it will make them skinnier/prettier/healthier… And frankly, I don’t think it is a whole lot more far-fetched than some claims people make (Cordyceps infested caterpillars as a performance enhancer!).

    If it actually gets around, it can only educate people (let’s face it – no one in Britian actually has 300 bot flies with which to do this and a tarantula head massage is perfectly benign). People may actually lean a little bit about biology – say what a bot fly is, its awesome life history or the cranial nerves (on old olympus, towering…). Maybe that last point is asking too much.

    Let’s suggest more!

  6. oh, come on, this insecticure website is obviously a hoax, isn’t it? and a fairly funny one as well.

    • In all likelihood, yes, it is probably a hoax, but there are a lot of people out there who are either extremely gullible, or desperate to lose weight, and who might be susceptible to believing this is possible. Better to set the record straight and try to prevent an urban legend from being born!

  7. There is no limit for human creativity… and stupidity!
    I am going to share this if you don’t mind – there is some excellent info in your post that all people should know about botflies.
    By the way, I am not sure if I mentioned this, but I was harboring three botfly larvae when I visited you guys in Guelph. I planned to rear at least one to adulthood, but things went bad somewhere along the way and their locations got infected – forcing me to have the larvae removed.

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