Minute to tiny flies at only 1-3mm in length, biting midges can be a severe pest of humans, pets, livestock and wildlife. Known by many common names including “no-see-ums”, “punkies” and “five-O’s”, depending on the region of the country you are visiting, biting midges can be extremely annoying. Although they are not known to transmit human related diseases, there are animal related diseases that are spread by biting midges of which Blue Tongue virus in livestock is likely of the greatest importance. Adult biting midges inflict a burning sensation and can cause a wide variety of reactions in humans ranging from a small reddish welt to allergic reactions resulting in severe itching at the site of the bite. When not engorged with blood, biting midges are typically grayish in color. Wings contain dark patterns giving them a grayish appearance as well. Their mouth parts contain four miniscule blade-like structures that lacerate skin creating the burning pain felt during bites.
Male and female biting midges feed on nectar and plant sap, which are their primary energy sources for flight and increasing the longevity in females. Only female midges are capable of biting and feed primarily on mammals, although they will also feed on birds, reptiles and amphibians. Some species are host specific, whereas others are opportunistic and are triggered in response to carbon dioxide emitted by a potential host. In order to produce eggs, the females of most species of biting midges require a blood meal in order to produce eggs. Females lay eggs in masses on a variety of moist surfaces. Larvae hatch in 2-7 days. There are 4 larval stages and rate of development varies greatly depending on temperature and food supply. Larval development can be completed in as few as two weeks or may last as long as a year or more. Appearance of larvae will vary depending on the species and can resemble a worm or caterpillar-like body. Following the larval stage, pupae are formed and adults emerge in 2-3 days. Typically, adults live for an average of two to seven weeks. It is estimated that two to three generations of biting midges are produced annually with last stage larvae overwintering in order to pupate the following spring or early summer.
Some species are attracted to light, which typically encourages their attraction to areas where human blood meals are available in the latter part of the day. Reducing lights around the home will help to decrease activity from these biting midges. In general, control of biting midges in both the larval and adult stages is difficult due to their small size. Thorough sealing of the structure and installing fine mesh designed for prevention of midges on window screens may assist in decreasing activity. Insecticide control of biting midges provides limited success as do repellents containing DEET. Avoiding outdoor activities during times of peak activity is often one of the best ways to avoid being bitten.