Location: Agroecosystem Management Research
2018 Annual Report
Objectives
Objective 1: Develop sustainable methods for the management of stable flies and other flies impacting livestock production.
Sub-objective 1.1 Identify and test larvicides for stable flies and other flies developing in livestock wastes.
Sub-objective 1.2 Develop attractants for use on traps.
Sub-objective 1.3 Develop adult fly repellents with extended residual activity.
Sub-objective 1.4 Evaluate effects of stable flies on behavior and productivity of cattle.
Sub-objective 1.5 Evaluate the effectiveness of a Push-Pull stable fly management strategy.
Objective 2: Characterize effects of biological, chemical, and physical substrate properties on stable fly larval development.
Sub-objective 2.1 Characterize functional groups of microorganisms in substrates associated with stable fly and house fly larval development.
Sub-objective 2.2 Identify endosymbionts and parasitoids associated with stable flies.
Sub-objective 2.3 Characterize nutritional factors required for stable fly larval development.
Objective 3: Develop a physiologically based demographic model (PBDM) to predict temporal and spatial patterns of stable fly population dynamics under current and potential climatic conditions.
Sub-objective 3.1 Determine physiological responses of stable fly developmental stages to environmental variables.
Sub-objective 3.2 Incorporate parameters from 3.1 into PBDM.
Sub-objective 3.3 Validate PBDM.
Approach
Stable flies are among the most serious arthropod pests of livestock in the United States, costing producers in excess of $2 billion per year in lost production. They exhibit an extraordinary ability to adapt to, and exploit, regional agricultural and animal husbandry practices. Stable fly management has proven to be a daunting task largely due to their adaptability, mobility, and gaps in our knowledge of their behavior and biology. This project will address all of these issues. Primarily, the project will develop new methods for the management of stable flies by exploiting the most vulnerable stages in their life cycles. Secondarily, we will develop a better understanding of stable fly biology and how they interact with their environment and hosts. Finally, new and existing information on stable fly biology will be incorporated into a dynamic, physiologically-based demographic model. This model will permit us to predict the dynamics of stable fly populations under real and potential environmental conditions, as well as provide insight into the validity of our understanding of their interactions with biotic and abiotic factors in the environment for development and reproduction. Successful completion of this project will result in new technologies for the management of stable fly populations, reduced impact of stable flies on livestock production systems, and a greater understanding of their biology for the continued development and evolution of stable fly management technologies.
Progress Report
New technologies for the management of stable flies were developed and evaluated. A new Insect Growth Regulator formulation was found to effectively reduce the emergence of adult stable flies from hay feeding circles by over 80%. Methyl laurate, a newly identified coconut fatty acid derived compound exhibits strong toxicity against adult stable flies as well as strong repellency. A starch-based coconut fatty acid formulation developed in collaboration with ARS, University of Nebraska - Lincoln and Costa Rican colleagues, deterred stable flies from laying eggs and acted as a biopesticide. An insecticide impregnated screen for stable fly control and several trap designs, including a new pre-glued card trap, were evaluated at a cooperator’s dairy farm. A collaborative investigation involving scientists at Clay Center, Nebraska, Kerrville, Texas, University of Tennessee and University of Arkansas to identify genetic markers associated with cattle susceptibility to horn fly infestation continues. (Objective 1).
New stable fly attractants were identified. A new compound identified from byproducts of sugarcane fermentation, 2-phenyl ethanol, was found to attract stable flies. This compound yielded strong electroantennagram responses from adult stable flies. Traps baited with this compound tested in the field showed 130-150% higher catches of stable flies compared with traps without the attractant. m-Cresol impregnated glue developed for an auto-trapping system for stable fly mass trapping is being evaluated as part of a Cooperative Research and Development Agreement. (Subobjective 1.2).
The role of flies in the dissemination of antimicrobial resistant (AMR) bacteria is being evaluated in collaboration with scientists in Clay Center, Nebraska. The investigation is part of a larger study on the ecology of AMR bacteria and genes at Clay Center, Nebraska. (Subobjective 2.2).
Carbohydrate sources (wheat bran, oats, rice bran), protein sources (fish meal, albumin, casein, soy protein) and bulking agents (fine pine shavings, straw, cob pellets, vermiculite, coarse pine shavings, pine pellets) were evaluated for stable fly larval diets. (Subobjective 2.3).
Flies collected from diverse geographical regions of the United States and Canada for the life history study have been sexed, counted, wings mounted and measured. Ovarian age of females was determined. Individual flies are stored for DNA analyses. Flies from Ontario were recently received and are being processed. (Objective 3).
Accomplishments
1. An attractant-impregnated sticky film for stable fly mass trapping. Biting flies can cause local and systemic effects that lead to infectious or inflammatory responses in livestock, companion animals and humans. USDA-ARS scientists in Lincoln, Nebraska identified attractant compounds associated with cattle and their environment. When incorporated into traps, these compounds enhance biting fly captures. As part of a Cooperative Research and Development Agreement, this technology was developed into a novel attractant-impregnated sticky film. A proto-type product is being tested for stable fly mass trapping in cattle feedlots. More effective traps will reduce biting fly damage to livestock and are especially effective in organic systems were few other options are available.
