Whilst most of us think of insects as causing illness, throughout history different cultures and civilisations have utilised insects as part of their medicinal tradition. Most of us are familiar with the use of leeches but it goes beyond this and today I’ll be looking at a few of the ways insects have been used to treat illnesses in the past.
First a quick glance at the ubiquitous leech. To understand why they were such a popular treatment we must first know a bit about how the body, and health, was viewed. It was thought that the body was made up of different humours and that health depended on a careful balance of these, one of which was blood. When you were ill, it was down to an excess or lack of a particular humour and so, if you had too much blood, it made sense to get rid of some. With this lens on the human body, the obvious thing to do was to use bloodsucking creatures, like the leech. Leeches are great at sucking blood. They drink a lot at once and are thought to have numbing properties in their saliva which mean you don’t experience pain with the bloodletting. Conditions treated by leeches were numerous and included black eyes, headaches, fevers, obesity and melancholia. It was so popular as a treatment that in 1883, French medical professionals imported over 40 million leeches. Today, we use leeches to help heal skin grafts and to help reattached body parts with blood circulation.
Turning our eyes to the past, we find cockroaches used to treat measles, grasshoppers to stop fits and bed bug broth to cure malaria. We also see the use of sympathetic medicine, that is if something looks like the illness then it will treat the illness. Examples of this include using dung beetles for constipation, hairy creatures like tarantulas for hair loss and stick insects for weight loss. Dried and powdered earwigs were mixed with rabbit urine and poured into the ear to cure deafness. A particularly icky practice was that of inserting beetles into the womb to irritate it and bring on a late period in ancient Greece.
Insects aren’t just used to treat illness but have also been used as a medical tool. One particularly interesting example is that of encouraging ants and termites to bite a patient as a means of getting medicine inserted subcutaneously.
Despite insects being used in medicine for thousands of years, there was a move away from them as science developed in the 19th century. But today, we are starting to re-explore the insect world in the hope of finding solutions and treatments there, this time through a scientific lens.
Because insects inhabit almost every part of the world, they have come across a wide array of predators and have had to adapt innovative strategies to defend themselves. Like the defences found in the oceans, these may have medical benefits to humans.
Maggots were found to be excellent in promoting wound healing by military physicians. They noticed that soldiers who had maggot infested wounds fared better than those who didn’t. Today we use maggots to liquefy dead tissue, to kill harmful bacteria and to stimulate healing in burn patients.
Honey is found in healing all around the world and has been shown to have antimicrobial and anti-bacterial properties. It has been used to treat a wide range of ailments historically including scar tissue, rashes, burns, digestive issues, colds, coughs and sore throats.
We know that blowfly larva produce a chemical which has uses as an antiviral and the venom of a particular type of wasp can kill cancer without harming healthy cells. Ants produce an antimicrobial to control bacteria as, being social creatures, they have a high chance of encountering germs. They also stay healthy by eating toxins when they are infected, by collecting conifer resin as a preventative measure and produce formic acid which combines with the resin to produce antimicrobials.
Blister beetles have been found to treat warts and other skin problems and bloodsucking insects are being explored as their saliva contains anticoagulants which may have medicinal applications. Spider silk is being explored for use in sutures, to heal wounds and to act as scaffolding for ligament generation and silkworm silk is being looked at with a view to using it to create artificial bones.
Traditional knowledge and healing folklore may seem laughable today but, sympathetic healing aside, we can turn to these practices to gain insight into where we may want to look for treatments today. Our ancestors didn’t always know why something worked but often their practices have merit when considered through a microscope.