Vampire insects in search of blood meal

Horn Flies are one of many species of insects that drink the blood of a another animal. These flies are born on the dung of mammals and drink the blood of their hosts to survive at a young age. (Scott Bauer/Wikimedia Creative Commons)

A little brown moth drills its long hook and barbed wire mouthparts into the flesh of an unsuspecting mammal, wagging its head from side to side and sucking up blood from its piercing tube. This isn’t your usual blood-sucking pest, but it’s among hundreds of vampire insects that somehow evolved an appetite for blood. 

We think of moths as innocent creatures that drink the nectar of flowers in the night, but we have been deceived. 

Calyptra, a genus of blood-sucking moths aptly named "vampire moths", is thirsty for blood and can go as far as piercing through the hide of a buffalo to snag a drink. They are mostly confined to Malaysia and southern Europe, but are quickly finding homes farther north in Sweden and Finland. Unlike the persistent female mosquitoes we all know and dread, only male vampire moths drink blood while females pierce into fruits to get at the sweet juices inside. 

So how did vampire moths or any other insect adopt such a bloody diet? Most insects, over 99.99 percent of them, don’t drink blood, choosing alternative diets of mostly other insects or plants, but blood-feeding insects may have had their roots in a variety of places. Vampire moths already had the ability to pierce fruit and they may have repurposed that ability for piercing into mammals. 

Other blood-feeding insects may have begun their vampire life styles as a result of their fondness for dung. Female horn flies, for example, lay their eggs in vertebrate poop within 15 seconds after it’s laid, but they probably had to find a way of making sure they could get to the dung while it was still fresh and well-suited for their young. They probably hitched a ride, permanently adapting their lives to living on mammals and waiting until the mammal pooped. While they lived on it, they would have had to drink its blood for nutrition in order to produce more young. 

For us, blood-feeding insects are some of the most terrifying creatures on earth and it’s not because of how they look. Mosquitoes are often considered the most deadly animal in world because they kill over a million people every year by transmitting malaria, according to the World Health Organization. Tsetse flies are just as dangerous, killing more than 20,000 every year through sleeping sickness and causing billions in livestock damage. 

When these animals feed, their abdomens become bloated with blood because in the case of tsetse flies, they must take advantage of any chance they get to eat. After all, drinking blood from large mammals is a dangerous task for these small insects. 

Tsetse flies may just be the most horrifying creatures yet. Even as vampires, they produce milk and give birth to larvae instead of laying eggs. Many of them have cutting, saw-like mouthparts to slice into flesh for their bloody meals. 

Whichever blood-feeder you consider, insects like these give a new meaning to vampirism, one that’s arguably a lot more bloodcurdling than whatever we could have imagined.


Diler Haji is a staff writer for The Daily Campus. He can be reached via email at diler.haji@uconn.edu.