Stable Flies

The stable fly (Stomoxys calcitrans) appears similar to house or flesh flies. With mottled black-brown bodies and bulbous, complex eyes, stable flies typically measure 7 to 8 mm in length. They are serious livestock pests, affecting cattle, chickens and dogs. They can also bite humans.

The mouthparts of the adult stable fly enable them to pierce and suck to obtain blood for food. Unlike other species of biting fly, both male and females feed on blood. Stable flies feed several times during egg laying, and one fly can be responsible for multiple bites. If infestations become severe, production and animal health will suffer. Stable flies focus on the legs of affected animals, and livestock experiencing stable fly bites stamp their feet frequently against the ground.

Female flies seek decaying organic material within which to lay eggs—wet straw, old manure and wet grass clippings are ideal egg sites. The full life cycle of a stable fly in hospitable conditions is generally one month.