Location: Agroecosystem Management Research
Title: Stable Fly Research Authors
Submitted to: Nebraska Agricultural Experiment Station Bulletin
Publication Type: Experiment Station
Publication Acceptance Date: December 15, 2007
Publication Date: January 1, 2008
Citation: Taylor, D.B., Berkebile, D.R. 2008. Stable Fly Research. University of Nebraska Lincoln Extended Visions. January/February 2008. 12(1):2 Technical Abstract: Adult stable flies feed on the blood of humans, pets and livestock, inflicting painful bites. Stable flies need one and sometimes two bloodmeals each day to develop their eggs. Unlike mosquitoes where only the females bloodfeed, both male and female stable flies require blood to reproduce. Stable fly maggots live in fermenting or decomposing vegetative material such as silage, spilled grain and hay or straw mixed with animal wastes. Historically, stable flies have been primarily associated with confined livestock in the barnyard environment. However, improved sanitation by the removal or covering of potential developmental sites has greatly reduced their numbers in confined livestock operations. Over the past 20 years, livestock producers have switched from feeding pastured cattle small square bales to large round bales during the winter. Cattle can waste up to 50% of the hay at large round bale feeding areas. This waste hay combined with manure and urine provides an ideal habitat for stable fly maggots. With the expansion of the stable fly habitat to pastures, their economic impact on livestock producers has increased to an estimated $1 billion per year. This does not include their impact on companion animals and human recreation. The USDA-Agricultural Research Service (ARS) Agroecosystem Management Research Unit, in collaboration with the Department of Entomology, has been conducting research on stable flies at the Agricultural Research and Development Center (ARDC) for nearly 30 years. This facility offers unique opportunities to study stable fly development, migration and feeding in a diverse agricultural environment. Current research focuses on characterizing winter hay feeding sites in the pastures, quantifying stable fly development in those sites and developing cultural, physical and chemical control technologies to eliminate stable fly larvae. Related research involves monitoring adult stable fly movement after emerging from developmental sites to search for blood meals. This information is important to determine how large an area must be included in a control program to reduce stable fly numbers. Weather parameters (temperature and precipitation) are used to develop models to predict stable fly population levels. Information from such models can be used to alert producers of the impending need to implement control procedures. Researchers have estimated that as many as a million stable flies can develop and emerge from a winter hay feeding circle. Given that producers will frequently locate three to five feeders in a pasture, these sites can be tremendously productive. Most of the flies emerge from these sites from mid-June through early-July. Few flies emerge after this time. Generally, flies move an average of 1 kilometer (0.6 miles) in search of blood meals, but flies that develop in materials near livestock concentrations do not move any further than necessary to find hosts. Once adult stable flies locate a herd of cattle, they stay near the hosts, bloodfeeding daily until the female’s eggs have matured and she begins to search for a suitable site to lay her eggs beginning the cycle over again.