PASTURE PEST MANAGEMENT: ADVANCING THE IPM TOOL BOX

<b>Project Methods</b><br> MethodsObjective 1. Containment and mitigation of Asian longhorned tick in North Carolina. Develop environmental sampling strategies to monitor tick populations in and around the pastures. Active surveillance as defined in the ALT Sampling Response Plan (USDA 2019) relies on tick drags made from readily available materials and assembled following instructions provided by the US Army (https://youtu.be/uJAbkSQrK84). Pulling the drag through the vegetation allows questing ticks to transfer to the cloth. At 30 to 50 meter intervals, ticks removed from both sides of the drag are stored in ethanol for identification. ALT's will be sent to the National Vet. Serv. Lab. for molecular confirmation. Confirmed counties will be added to the USDA APHIS database tracking the movement and host range of the tick. In collaboration with NC Dept. Agric., a subsample of the ALT collection from cattle will be prepared for pathogen screening https://www.vet.cornell.edu/animal-health-diagnostic-center/testing/protocols/tick-evaluation. Of particular interest is Theileria orientalis Ikeda, a potentially fatal blood-borne parasite of cattle transmitted by ALT. This protozoan has not occurred in NC, but was found in four VA counties bordering NC (Lahmers 2020 https://wvstateu.edu/wvsu/media/Outreach/VMCVM-Theileria-summary-1-14-20.pdf).Subobjective 1a. Develop a protocol for producers and researchers to follow to recognize infestations in the early stages. Best management practices for managing ALT include quarantining and palpating new animals before they join the herd. Extra attention should focus on the ears, head, rump, tail head, perianal region, udder & scrotum, and axillary regions. Treat all new stock before introduced to the herd.Subobjective 1b. Develop treatment strategies for producers to protect herds and the environment from this invasive species. ALT is susceptible to pyrethroid and macrocyclic lactone acaricides applied as a spray or a pour-on treatment. Environmental treatments should be used when populations are extensive and only as directed by the label.Subobjective 1c. Cultural conditions conducive to recurrent and persistent populations of ALT may be manipulated to prevent rebounding infestations. Tick eggs are subject to desiccation and mowing pastures increase egg exposure to lethal temperatures and drying. For comparison, data loggers placed in the environment will record microclimate conditions in mowed and unmowed pastures and infested and un-infested pastures.Subobjective 1d. Extension and outreach. Best Management Practices for surveillance, on-animal and environmental treatments, and cultural practices will be provided to the livestock producer community through grower meetings and electronic media. Agent training on the recognition and identification of the tick will be provided to all county agents with livestock responsibility in the form of webinars, fact sheets and pest reports.Objective 2. Study of the Appalachian dairy industry on pest and disease impediments regionally. This is a USDA OREI funded collaborative project between NCSU CALS Department of Animal Science, Stephanie Ward, and CVM Department of Population Health and Pathobiology, Kevin Anderson. The proposal seeks to improve systems-based animal production, animal health, and pest management practices while enhancing economic viability.Subobjective 2a. Survey of organic and conventional dairy farms to determine current management practices for fly control through mailings and on-line surveys. Survey questions ask producers about pests of concern, seasonality, severity, control strategy, confidence in the control strategy, disease or welfare concern, economic impact, informational sources, and willingness to participate in a larger project. We intend to expand the on-line survey to include NE, KY, TN, GA and others. The incoming data from the NC survey (40% return) is being prepared for analysis.Subobjective 2b. Planning meetings, Focus Groups, and Work SessionsThis project includes two planning meetings with the primary focus to develop a full proposal, review survey data, project approach and budget, and recruit farmers for on-farm research projects.Producer based focus groups will be held in the participating states. Farmers (both organic and conventional), extension agents, and industry support personnel will attend the focus groups. Interviews will be guided by a protocol requiring specific topics to be addressed (current fly management practices, perception of impact of flies on diseases, etc.) but still broad enough to allow flexibility for all relevant factors to be identified and explored.Objective 3. Dispersal potential of horn fly, face fly and stable fly. The movement of flies from location to location interferes with the management plan of many cattle producers as invading flies compromise existing control strategies. Organic dairy producers may use essential oils as repellents for pasture flies. Repelled flies disperse from the cattle and are assumed to seek out untreated cattle nearby. To gain a better understanding of fly dispersal potential we designed a flight mill tool capable of measuring maximum distances, average and maximum individual speed, average fly speed and distance.Arduino microprocessers (https://www.arduino.cc/) were used to track insect flight distance, time in flight and speed. To create a flight mill light enough to measure flight of small insects, we used 000 insect pins with the head removed as a staff and the cross member. The cross member had a 5 mm 90o bend at one end to hold the fly and a mylar flag opposite. The cross member was centered and soldered to the staff. The staff was suspended in place between a magnet and a guide base. An infrared beam was used to detect each revolution of the mylar flag. Distance was calculated based on revolutions per minute times the circumference of the flight path. Proposed experiments will examine the flight distances of wild flies and colony reared flies at different ages and feeding regime (unfed teneral, and fed 2d & 5d old flies). Field collected wild flies will be reared to the first generation for testing. Laboratory reared horn flies and stable flies will be provided by USDA ARS Labs under a signed MOU. Face flies are currently maintained in-house.Objective 4. Develop a vacuum fly trap amenable to both dairy and beef cattle production. For this study, a uniquely designed vacuum powered walk through fly-trap removes flies from cattle as they pass through (Denning et al. 2014). This electric fly trap is particularly suited for dairy operations and less so for beef operations or farms where electricity is a challenge. We have increased the utility of this trap by adding a propane power source making it amenable to beef cattle production or isolated dairy use. Additional modifications include durable but lightweight ultrastructure and mobility desired by cattle producers. Cows trained to use the walk through fly trap to access water or supplemental feed and are expected to pass through the trap at least once each day to remove the flies. A control group of similar size will not use the trap. Fly densities will be determined by 1) a trained observer will estimate the number of flies weekly on 10 randomly selected cows within the larger group, 2) with digital photographs of the same 10 animals. Flies in recorded images will be quantified using the GIMP 2.10.18, GNU Image Manipulation Program (Boxler et al. 2018). The recorded number of flies for each animal and the group means and standard error calculated. Weekly, we will quantify the number of flies captured by the traps by removing the collection container and freezing the flies contained within. Flies will be air-dried, weighed, and the total number of flies captured per week calculated by extrapolation from subsamples sorted to species.