Stable Flies

Stable Flies

stable fly
Stable fly photo by UNL Entomology Dept.

Stable Flies: Plague People, Pets and Livestock

The stable fly is a nuisance fly which inflicts painful bites to feed on blood. It can be found in rural, urban and suburban areas wherever breeding sites are found. With all the rain this year, moist breeding sites in both rural and urban areas are abundant.

Stable flies look superficially like house flies, but with an important difference. . . they have long bayonet-like mouthparts used to bite and suck blood. They are also popularly referred to as “biting house flies” and “dog flies”. Stable flies can be a serious problem for livestock and dogs kenneled outdoors.

Because of its name, many people probably think the best place to find a stable fly is in a stable, but they are hardly ever found there. In rural areas, eggs are deposited in wet, organic materials such as straw, litter, manure mixed with straw or other bedding, soggy hay, waste silage or feed in feedlots. In urban areas, stable flies will breed in wet piles of grass clippings, vegetable or fruit matter or compost heaps. Many experts believe the most common breeding site of stable flies in municipalities is dog feces.

Eggs hatch in 1-3 days into tiny maggots which begin to feed. The last stage maggots often crawl away from the breeding site and pupate in the soil. Pupae are chestnut brown and have a seed-like appearance.

Total development from egg to adult fly takes 3-4 weeks, depending on temperature.

Unlike mosquitoes, both male and female stable flies bite. Stable flies are active during the daytime. They bite standing animals, including people, on the legs and ankles. They bite resting dogs on the ears. Stable flies need 2-5 minutes to complete a blood meal which is often interrupted. They may “bite” several times to obtain a single blood meal.

Control: Eliminate breeding sites

  • It seems too simple, but scattering breeding material regularly to dry it out is the most effective method of control. This will deny the fly maggots a moist breeding site.
  • Turn piles of compost to encourage rapid decomposition.
  • Do not dump lawn clippings in piles after mowing.
  • Clean up after pets; remove pet waste twice a week to prevent fly development. Put feces in plastic bags and in the trash.

Chemicals

  • The use of pesticides is usually not the best means of managing stable flies, but there are situations where it may be helpful.
  • Residual insecticides can be applied to outdoor surfaces where flies rest, such as the outside surfaces of barns, stables, doghouses and fences. (Note: Surprisingly, stable flies are most attracted to surfaces painted white.)
  • Registered space sprays/foggers can be used in livestock barns to kill flies resting on surfaces.
  • Advantix® (Bayer HealthCare), is a topically applied product that has been tested on dogs against stable flies. Studies have shown it has been shown to repel stable flies and reduce feeding by 80-90%. This product also protects dogs against mosquitoes, ticks and fleas.
  • People may be able to get some repellency to prevent bites from stable flies by using repellents containing DEET and picaridin. Spray lower legs where stable flies are likely to feed. For best efficacy, you may need to use products with higher percentages of active ingredients.

Other suggestions

Wear long pants and socks to prevent stable flies from biting you. Dave Keith, former Extension Entomologist, suggested that when you wear shorts you should wear dark colored socks (rather than white ones).

Note: For your safety, as well as to be in compliance with Federal laws, always read, understand and follow pesticide product label directions.

Barb Ogg
Emeritus Extension Educator, Entomology
Barb Ogg shared her love of entomology with clientele throughout Nebraska for many years through Nebraska Extension. Barb retired in 2015.

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