Medically Important Insects


Insects cause us grief in a variety of ways, which is why we have unfavorable opinions of these six-legged creatures. They’re not all looked upon with such disdain – butterflies, ladybugs, dragonflies, and antlions elicit pleasant thoughts in most people – but the ones that affect human health are a real cause for concern. I’ll touch upon the ones that are medically important but, for the purposes of this article, we’ll leave out the eight-legged arachnids, which includes the spiders, mites, and ticks and talk about them some other time.

The most obvious bad bugs are the ones that sting. These include ants, bees, wasps, and some caterpillars. In our area, the stinging ant of importance is the fire ant. Those with limited mobility, like infants and the elderly, have been killed by being overwhelmed with fire ants and essentially being stung to death. Most often, though, severe and sudden allergic reactions cause most fire-ant-related deaths. This can happen with any venomous insect, to include bees and wasps. Honey bees, bumble bees, yellow jackets, hornets, and paper wasps are all venomous, stinging insects that are defensive of their colonies. Most deaths are from allergic reactions, and from people who stumble upon a nest unknowingly. Stinging caterpillars, like the saddleback and puss moth caterpillar, are lesser known threats. They don’t move quickly but can be accidentally grabbed, resulting in their hollow, venomous hairs being broken off into the skin. The sting is reported to feel like stinging nettle and one of the worst stings you can get from an insect.

The second most obvious bad bugs are the ones that bite and suck blood. Mosquitoes, horse flies, bed bugs, fleas, lice, and kissing bugs fit into this category. While bed bugs don’t transmit any diseases that we know of, the other bugs in this list do. Mosquitoes transmit malaria, the biggest killer of humans on the planet, as well as dog heartworm and a host of other terrible, debilitating diseases.

The other medically important bugs are not as obvious. German cockroaches are responsible for a high incidence of childhood asthma. Children growing up in infested homes are constantly breathing in airborne cockroach particles from shed skins, saliva, dead cockroaches, and cockroach droppings. Living in these conditions greatly increases the chances of developing severe allergies and experiencing life-threatening asthmatic episodes.

Blister beetles are somewhat large, elongate beetles with soft wings. They have a chemical in their blood called cantharidin which causes blistering of human skin. Inadvertently touching or crushing these beetles can result in painful blisters. There seems to be some panic and misunderstanding on social media about this beetle, so let me clear something up. The blistering reaction is like a chemical burn and is not a bacterial infection. Oral antibiotics are not needed and should not be administered. The blisters will heal on their own, and it’s best not to bust them. Popping the blisters can result in a secondary infection, which is the case with any open wound on the skin. If the blisters rupture, wash well with soap and water and keep the wound clean and dry. Apply antibiotic gel if you are concerned with infection of the open wound, but oral antibiotics prescribed by a doctor are not needed. Eating these beetles is a bad idea, as cantharidin is very toxic to mammals. Horses occasionally die from ingesting these beetles in baled hay.