That pests are annoying and a health hazard, we should have made clear by now. However, who would have expected flies to use mosquitoes to reach their feeding place?
Meet the Human Botfly, Dermatobia hominis. Adult human botflies are stout-bodied flies. They have no active mouth parts and thus do not feed. They are found in Central and South America, and mostly specialize on cattle. However, it is not uncommon for humans to get in contact with them.
So far, so good. Flies without mouth parts cannot be much of an annoyance, right? Yes they can. When it comes to reproduction, the female botfly catches a female mosquito and lays its eggs on the mosquito. Pests disturbing each other are still fine with me.
Now comes the evil part, once the mosquito bites a host, the fly larva hatches and digs through the skin of the victim. Once inside the flesh it forms a kind of tumor, called a warble (even the name sounds scary), where it rests and eats. It breathes through a tiny opening in the skin. In the beginning it is usually not noticed, but it grows up to a size 20mm and has rows of hooks on its body, to keep it in place. This definitely will cause a swollen, itchy and painful lesion.
Now, even though this might be disgusting, the good news is that there are no dangerous diseases transmitted if it should happen to you on your travels. There are various easy ways of removing the maggot, e.g. using your fingers and pressure to pop it out, or sealing the breathing hole and forcing the larvae to come out.
I never really liked flies, except maybe as pet lizard food, but this really is scary, and if it should ever happen to anybody, it will for sure top any other holiday pest story. The peak fly season is about to start here, and I am happy I am on a different continent, where we only have to control “harmless” houseflies, that will be attracted by our Luminos traps rather than our flesh.
On a side note: There are more botfly species, which are mostly specialized on animals and not necessarily use mosquitoes as a vector. For example, there is a species that catches houseflies, holds them in a tight grip and then lays its eggs near to the wings of the caught housefly. Once the housefly sits on an animal, the eggs hatch and the whole warble thing (as described above) takes place.
14 Comments
This is gross! I hate the very thought of it but what does Rentokil do about it?
This article made me feel really quite ill at first; then I realised that it also reminded me of growing up in Zambia where there is a fly that lays it’s eggs in seams of damp washing. These eggs then burrow into your skin and from them a maggot hatched inside you!
Prevention? We ironed EVERYTHING, including underwear as this killed the eggs but …. if something got ‘through’ then you smeared vaseline or another barrier cream over where all these eggs were to suffocate the maggot. Once they had ‘suffocated’you could ‘pop’ them out like squeezing a spot!
For the love of God, keep writing these artleics.
I am wondering if with the climate change – (just to remind you, global warming caused by humans has been officially called off, now it’s called “the climate change” and has nothing to do with us) – some of these pests would not come to more moderate climate regions … brrr, terrifying
from now on, I will look at our good old houseflies and mosquitoes in completely different way and appreciate how lucky I am… and then smash them as usual
I saw this on ER Stories where Dr Bush, I think from Texas (he is the snake expert). It was gross, the person had a human botfly in his skin. Really gross..
The fly referred to by Caroline, that lays it’s eggs in damp washing, is called a Putsi Fly. It is quite a problem to tourists who do not think to iron, for example, swimwear!
This is truely disgusting! I have friends on honeymoon in South America at the moment…I hope someone has warned them about this! Though I doubt they would have packed their iron anyway! Thanks for the warning.
Putting the washing straight in a tumble dryer would stop the laying of eggs – and might even be hot enough to kill of any eggs already there.
Mind you, using electricity instead of sunlight to dry clothes will only hasten climate change and bring some of these pests closer to those of us who live in colder climates…….
The reason Richard so knowledgeable about the Putsi Fly is that I am his wife and left my bikini bottoms on the arm of a deckchair overnight, when holidaying in Central Africa. I most certainly did not iron it and a few days later had red blister like spots that clearly outlined the seams of my Bikini bottoms. These were actually where the maggot of the Putsi Fly was inside me … need I tell you more??
In reply to Jim Gubbins, (first comment), I will pass your enquiry on to our technical people but I am actually pretty sure that we would recommend the same 5 basic steps as outlined in Brigitta’s post:’How to Get Rid of Flies – Mr Miyagi Style’ [http://www.rentokil.com/blog/how-to-get-rid-of-flies-mr-miyagi-style/]
This is really interesting as I didn’t know the maggots were root-caused by human botfly. Had seen some pics in email which were forwarded so many times so not knowing who the original author is, and the email was lack of information. So now it feels good to know more details about this.
I live in Vermont, have had no travel farther south than Indiana this summer and just pulled a botfly larvae out of my leg after a two week itch-a-thon and – what I thought – was a forming cyst. We thought it was a tick bite that became infected and a doc put me on antibiotics as a precaution for Lyme’s. At least I can stop worrying about that! The big question is, where did I get this thing? Vermont? S. Indiana? Martha’s Vineyard? That’s the extent of my summer travels and none of these places, you will note, are in South or Central America. Climate change, it appears, is not all about droughts and floods.
Hi Tom,
Bad to hear that. Good to hear though you got it out. I am somewhat dazzled by the fact that you got it that far North. But there are a few possible explanations for this.
1. A warm summer and international tourism might have transferred a fly to the areas, where you ran into it.
2. There is a number of bot fly species globally that have specialized on different hosts, such as the equine bot fly (which develops in a horse’s stomach), Caribou bot flies, etc. By mistake, you might have gotten in somewhere along the way of normal transmission and got the maggot. I think this is a more likely explanation. If human bot flies would have made it to the USA, I am quite sure media would mention it.
I hope everything is alright now. Thanks for writing. One last question from my side though: How big was the maggot and did you feel it moving inside the warble?
Regards
Ben
I can relate to Jo on this one, I had a week long visit to Central Africa.
On my last day of my holiday, I was preparing for a long flight, and I decided to wash my underwear in the hand basin, I put my panties on the back of a chair in the sun on the terrace to dry. Only at the last minute did I decided to change my underwear.
I never realised my damp underwear had been visited by a Putsi fly.
It was a few days after when I began to feel the effects. I didn’t know what to make of the small boils that appeared right between my legs, I just thought it was some kind of heat rash.
Things went from bad to worse, I felt quite sick for a couple of day, and I had awful pain.
It was very embarrassing, but I then went to see my Doctor. They gave me antiseptic cream and antibiotics. That eased things up for a week or so, but then it got really bad again.
Fortunately for me, a nurse who had spent time in Africa assisted the Doctor when I went back again, and recongnised what was going on. They used Vasoline to get them to pop out and they were then able to remove all five of them.
It’s something I’ll never forget.