Introduction: This fly receives its common name from its close association with stabeled domestic animals; they are also sometimes called biting house flies because of their similar appearance, and beach flies because of their abundance in beach areas. Stable flies are a pest because of the painful bite they inflict.
Recognition: Adults about ¼-3/8” (7-8 mm) long. Color dull gray with 4 black dorsal longitudinal stripes on thorax, with middle 2 stripes separated by a prominent pale area, and abdomen with nearly round dark areas. Head with proboscis/beak stiff, non-retractile, projecting forward from lower part of head.
Habits: Adults may take blood meals more than once each day but also feed on sugar sources. Although peak feeding occurs in the early morning and late afternoon on hot days, biting is diminished on cloudy and / or windy days. Stable flies are being referred to in the common expression “It must be going to rain, the flies are biting.” They attack the ankles of humans and the belly, lower body, and limbs of livestock, particularly horses and cattle. They not only agitate livestock but can cause a 40-60% reduction in milk production.