Location: Agroecosystem Management Research2020 Annual Report
OBJECTIVE 1: Determine the environmental predictors of stable fly outbreaks and dispersal. Subobjective 1A: Identify and model environmental variates associated with stable fly population dynamics. Subobjective 1B: Model stable fly population dynamics in differing climatic zones. OBJECTIVE 2: Investigate stable fly larval habitats to develop improved management strategies that protect livestock from stable flies. Subobjective 2A: Characterize the temporal and spatial dynamics of physical and biological parameters associated with stable fly developmental substrates. Subobjective 2B: Identify and develop stable fly larvicides and assess their sustainability. OBJECTIVE 3: Identify stable fly attractants and repellents for use in strategies to protect livestock from stable flies. Subobjective 3A: Identify novel stable fly attractant compounds from host animals and larval development sites (substrates). Subobjective 3B: Develop long acting formulations with spatial and contact repellency. Subobjective 3C: Identify and develop novel stable fly oviposition deterrents. Subobjective 3D: Incorporate products developed in 3A-3C into a comprehensive Push-Pull strategy for managing stable fly infestations and improving animal well-being.
Stable flies are among the most important arthropod pests of livestock and, with changing climate and agronomic practices, are poised to expand their roles as pests and disease vectors. Their painful bites reduce livestock productivity, annoy companion animals, and interfere with recreational activities. Recent estimates of the economic impact of stable flies on cattle industries in the United States exceed $2 billion. Current management technologies are unable to effectively manage stable flies. This project proposes to address the development of novel technologies for managing stable fly populations and their impact on livestock using basic and applied research. Basic research will address developmental biology and population dynamics. Applied research includes chemical control strategies, repellants for protecting animals, and attractants for improving the efficacy of trapping devices. Combined, these efforts will improve our ability to monitor stable fly populations, identify and manage larval developmental substrates, and protect livestock from their painful bites. Successful completion of this project will improve livestock productivity and producer’s profits, as well as reduce livestock stress and disease.
Objective 1. A dataset containing 9 years of stable fly trap catch data in northern Florida was analyzed with respect to the effects of temperature and precipitation. Contrary to previous studies in Nebraska, the relationship between trap catches and temperature in Florida was negative and precipitation had minimal effect. Two replicates of a study evaluating the effects diurnal temperature variation on the rate of stable fly development were completed. Objective 2. Analysis was completed on a study evaluating the relative sizes of stable flies collected emerging from substrates contaminated with animal wastes and adult stable flies collected on sticky traps. Results indicate that stable flies emerging from substrates containing animal wastes are significantly larger than those in the general adult population. The inference being that a significant proportion of the general adult stable fly population is developing in substrates with lower nutritional quality that those traditionally associated with their development. Studies were initiated to evaluate the microbial communities associated with laboratory stable fly larval developmental substrates with varying nutrient qualities. These studies will be extended to evaluate the microbial communities associated with field derived substrates. Objective 3. Attractant compounds associated with stable fly larval developmental substrates were tested on traps in the field. m-cresol, 2-phenylethanol, and pentanol, increased trap catches by 16-21%. Repellent compounds including coconut fatty acids and their derivatives elicited responses from stable fly taste receptors in single contact receptor recordings. Starch-pectin water based repellent formulation were tested against stable flies on cattle in North Platte, Nebraska pastures (third year of a Push-Pull trial). Coconut fatty acids and their methyl esters exhibited strong oviposition deterrence in both laboratory assays and field trials conducted in pineapple fields in Costa Rica.
1. Attractant-impregnated sticky film for stable fly mass trapping. USDA scientists from in Lincoln, Nebraska, in conjunction with an industry partner, developed an attractant impregnated adhesive tape for mass trapping stable flies. The traps can reduce stable fly induced stress and defensive behaviors of confined cattle by up to 80%. Cattle producers can reduce stable fly infestation levels with these traps resulting in improved weight gain and milk production of their cattle. An international patent was granted on this technology.
Roh, G., Zhou, X., Wang, Y., Cermak, S.C., Kenar, J.A., Lehmann, A.T., Han, B., Taylor, D.B., Zeng, X., Park, C., Brewer, G.J., Zhu, J.J. 2020. Spatial repellency, antifeedant activity and toxicity of three medium chain fatty acids and their methyl esters of coconut fatty acid against stable flies. Pest Management Science. 76(1):405-414. https://doi.org/10.1002/ps.5574.
Roh, G., Lee, Y., Zhu, J.J., Park, C. 2019. Morphology and distribution of antennal sensilla in egg parasitoid, Ooencyrtus nezarae (Hymenoptera: Encyrtidae). Microscopy Research and Technique. 82(7)972-982. Availble: https://doi.org/10.1002/jemt.23244.