Stable flies and pastured cattle

The stable fly, Stomoxys calcitrans (L.), likely introduced to North America with early European settlers and their livestock, has long been a significant pest of dairy and feedlot cattle. Both male and female stable flies feed on blood, typically attacking the lower legs and bellies of cattle. Their painful bites cause irritation and stress, leading to reduced milk production, decreased weight gain, and overall economic losses. Stable flies develop in decaying organic matter that contains soil, manure, and moisture. Consequently, a variety of management strategies have been developed to reduce their impact on confined livestock systems.

In the early 1980s, stable flies emerged as a serious pest of pastured cattle in the Northern Great Plains. This shift coincided with the widespread adoption of large round hay bales and ring feeders. Researchers soon identified hay spillage from these feeders, especially when moisture is present as an ideal breeding habitat for stable flies. This advancement in hay management unintentionally facilitated the expansion of stable fly populations in pasture settings.

Traditional management approaches used in dairies and feedlots proved ineffective against pasture-associated stable flies, prompting increased concern from ranchers and veterinarians. In response, research efforts were initiated to better understand the issue and develop appropriate solutions. This review will explore the impact of stable flies on pastured cattle, evaluate practical control methods, and highlight the development of novel control agents for use in rangeland systems.