Entomologist acts as human incubator for bot flies

Dr Piotr Nacklewski allowed two human bot fly larvae to grow to maturity under his skin (Photo: Shutterstock)

Entomologist and wildlife photographer Piotr Naskrecki is not squeamish. He recently allowed two human bot fly larvae to grow to maturity under his skin and documented the process in a short film.

Last year we wrote about a scientist whose commitment to science extended to not simply living with a tribe in Kenya to study their diet, but also administering his own fecal implant from one of the men of the tribe. Dr Piotr Naskrecki did not go quite so far but his incubation of two human bot flies under the skin in his arms, and his documentation of the process, is certainly a step beyond the general calls of science.

On a photography trip to Belize Dr Naskrecki went out on one of his last days to photograph red eyed tree frogs and forgot to slather on the DEET needed to keep mosquitoes at bay. He ended up being eaten alive but noticed when some of the bites didn't heal that they were actually spots where minuscule botfly larvae had dropped into the hole left by the mosquito bite.

The adult females typically lay their eggs on exoparasites such as ticks and mosquitoes and these hatch whilst still on their host. They then drop onto the skin of the human or other creature when convenient.

What to do? After removing some of the more painful larvae with a suction venom extractor – one can also suffocate them with raw steak and then pull the tiny corpses out with tweezers but you risk part of the larvae being left behind to rot and cause an infection – he decided to play host to the remaining two. "As strange as it sounds, I felt bad about killing them, but I also had never seen an adult bot fly and it was my chance." He also noted that as a man this was likely to be one his few chances to carry another creature to birth. It is, he says, something of a geeky right of passage for many entomologists.

The creatures grow from the size of a grain of sand to that of a peanut before making their way out of the hole or "warble" and dropping to the ground to burrow into it. "It is relatively painless, unless the larva decides to munch on nerve endings," he explains. The parasites may, he postulates, release some kind of antibiotic to stop infect in their hosts. They do release an anesthetic when escaping so their hosts barely notice what could otherwise be a painful departure.

The good doctor's blog and short film are both worth a read and watch. Though the latter is prefaced with a warning on how you cannot "unwatch" the footage, there is nothing particularly disgusting at any point. But, as always, thinking makes it so.

This is not life-changing science, but what makes it worthwhile is his simple deconstruction of human fears over "parasites". Why, he asks, do we love predators such as lions but abhor parasites such as the bot fly? The former can actually do us far more damage than the latter but we still prefer the fairness of a lion to the sneakiness of a parasitic predator. "To a bot fly we, humans, are a renewable resource – it is in the bot fly’s best interest that we live a very long life and thus can be “reused” – hence the minimum amount of suffering that this species causes. To a lion we are nothing more than a one-time meal. But we should not judge either species for their actions – there is no 'good' or 'bad' in nature – nature is amoral."

His facts about the botfly interspersed throughout the video are also interesting. Despite their parasitic beginnings the adults do not have working mouthparts and cannot bite, or even eat during their busy but brief few days of life.

Top stories

Recommended for you

Latest in Biology

Editors Choice