BY THE MASKED BIOLOGIST
I always do my best to emphasize that, no matter what I am talking about in the natural world, it has its place and serves a purpose. During this last spring turkey season, my oldest son asked me, “What good are mosquitoes?” Most people I know ponder this question. The typical human would quickly reply that mosquitoes are no good at all. They suck our blood, carry disease, and sometimes make it impossible to enjoy the Northwoods after a fashion we desire.
At the outset, mosquito benefits to humans are not readily apparent. They do not pollinate flowers and plants like bees. They do not have beautiful wings like butterflies. They do not break down dead matter into organic material like flies and maggots. They do not eat other, more harmful insects like dragonflies or beetles. What mosquitoes are good at is reproducing and drinking blood; this is the benefit they provide to the ecosystem.
To start with, a single adult female can lay up to 200 eggs. The eggs are very interesting; stacked in a raft, they look like boat bumpers or narrow buoys with floats so they can stay suspended on the water’s surface. Mosquito eggs are small, but they are a great source of food. When the eggs hatch, the mosquito larvae swim and feed underwater, but go to the surface to breathe. In the pupa stage, they stay in water but do not eat. During these stages, minnows, fish fry (newly hatched young), aquatic insects and some tadpoles will eat this high protein food source. Finally they morph into adults. Only the adult female drinks blood. These flying insects fill vegetation and the air. At this point, not only are they good food for fish, but for insects, birds, and bats as well. How much benefit is a matter of opinion and perspective. I have always heard that bats can eat 600 mosquitoes in an hour. While this may be possible, in reality the number is likely far lower. This number is derived from an experiment in the 1950s where a bat was released in a room with a known number of mosquitoes and they observed how many were eaten in a set amount of time. In the wild, however, I have seen bats select for moths rather than mosquitoes. Think about it—if you could walk up to a roasted turkey or run after a hot dog, which would you do? Purple martins, chimney swifts, and other members of the swallow family are also capable of eating thousands of mosquitoes a day. That might also be true if they couldn’t gorge themselves on lake flies, dragonflies, beetles and other larger food sources.
Dragonflies and other insectivorous insects eat mosquitoes, but rarely or never select strictly for them. Still, there is no denying that many different kinds of creatures include mosquitoes in their diet.
Finally, sucking blood makes them a disease vector. While we humans view this as a negative, a biologist sees the role that vector-borne illnesses can play in managing a population. It removes sick and weak individuals from a population, keeping the gene pool strong and advancing natural selection. It also helps reduce overpopulation, helping keep nature in balance. While it may not be the way we might choose to remove individuals or manage population levels, ultimately nature has the final say and mosquitoes are one of many means used to nurture or kill individual fish, insects, birds, and animals.
The Masked Biologist earned a bachelor of science degree from a university with a highly regarded Wildlife Biology program. He has worked for natural resource agencies from the Rocky Mountains, across the Great Plains and into the Midwest, which provided opportunities to work with a variety of common and rare fish, plant and wildlife species. Follow The Masked Biologist on Facebook.