The Horse Fly (Tabanus spp.) is variable — gray, brown, or black; iridescent compound eyes and typically measures ½–1¼ inches. Horse flies (Tabanus spp.) are among the largest flies in Arizona, with some species exceeding an inch in length. They are powerful, fast fliers with large, brilliantly colored compound eyes and sciss.

The Horse Fly poses a moderate risk. Extremely painful bites. Can transmit equine infectious anemia and other animal diseases mechanically. Significant livestock stress and economic impact near water sources.

In Arizona, horse flys are most often encountered in the following situations: Large, fast-flying insects near water. Extremely painful bites, often on the back, shoulders, or legs. Livestock showing agitation, bunching, and running behavior. Slow-healing bite wounds.

The Horse Fly is most active during: Late spring through summer; peak June–August near water. Arizona's warm desert climate can extend activity periods compared to other states, so year-round vigilance is recommended in the Phoenix metro and surrounding areas.

Avoid outdoor activities near water during peak activity (hot, sunny midday hours). Use DEET-based repellents. Dress in light-colored, long-sleeved clothing. Protect livestock with repellents and physical barriers.

No effective area-wide control for horse flies. Individual repellent use is the primary defense. Livestock management includes repellent ear tags and pour-on treatments.

Most fly species are drawn to food sources, moisture, organic waste, and breeding sites. For Horse Flys specifically: Large, fast-flying insects near water. Extremely painful bites, often on the back, shoulders, or legs. Livestock showing agitation, bunching, and running behavior. Slow-healing bite wounds.. Eliminating attractants is the first step — Pest Control Bros can identify the source and recommend targeted control.