Do Biting Stable Flies Overwinter Within Urban And Suburban Homes?

Do Biting Stable Flies Overwinter Within Urban And Suburban Homes?

The airborne insects commonly known as house flies (Musca domestica), and their many similar looking relatives like blow flies and cluster flies are commonly referred to as “true flies,” and like mosquitoes and gnats, true flies belong to the order Diptera. House flies, drain flies, phorid flies, and fruit flies are common indoor pests are often referred to as “filth flies” due to their habit of breeding on microbe-rich organic waste materials, most notably rotting food, garbage, animal carcasses, and excrement. Because of their filthy breeding habits, filth flies are considered potential mechanical disease vectors in human settings, but luckily, the odds of contracting a disease from fly-borne pathogens is slim unless humans are dwelling with heavily infested conditions. Filth fly pests are synanthropic species, which means that they have adapted to thrive within and around homes and buildings where they benefit from human activity. Unsurprisingly, the ten most commonly managed fly species on properties are all synanthropic filth fly pests, except for two species known as cluster flies (Pollenia rudis) and stable flies (Stomoxys calcitrans).

Cluster flies are not technically filth flies, as they are not associated with pathogen-rich breeding materials; instead, cluster flies are unique for laying eggs on earthworms, which their larvae consume to obtain the nutrients necessary to reach adulthood. Cluster flies invade homes in large numbers during the fall throughout New York state in order to secure warm conditions for overwintering. These fly pests are often referred to as “attic flies” due to their tendency to congregate in attics, but they also seek overwintering shelter within wall voids. Stable flies often breed on organic waste materials, and this species is also unique because it’s the only bloodsucking fly pest that is synanthropic. While stable fly females will readily feed on the blood of humans and their pets to meet the nutritional needs necessary to lay viable eggs, they prefer the blood of horses and livestock.

There is much debate concerning the stable fly’s status as an indoor pest, but some of the most thorough studies on this species has found that while they often congregate on the exterior walls of houses, they are not generally in the habit of entering homes. However, other sources state that cluster flies are common overwintering pests, but these reports may originate from individuals who mistook cluster flies for similar looking stable flies. The stable fly may be synanthropic only in so much as their preference for animal blood prompts them to congregate near horse stables and agricultural areas located near homes. On rare occasions, people sustain indoor bites from insects they believe were house flies, but were actually stable flies. Although a recent survey revealed that stable flies were the ninth most commonly controlled fly pests on residential and commercial properties nationwide, they prefer to remain outdoors, and it is unlikely to encounter specimens indoors in any geographic location.

Have you ever sustained an indoor bite from a fly pest?