PASTURE PEST MANAGEMENT: ADVANCING THE IPM TOOL BOX

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1007993
• Project Start Date: Oct 1, 2015
• Project End Date: Sep 30, 2020
• Program Code: [(N/A)]- (N/A)

Recipient Organization
NORTH CAROLINA STATE UNIV
(N/A)
RALEIGH,NC 27695

Performing Department
Entomology

Non Technical Summary
This project has two major goals; first my goal is to develop new tools for the management of pasture fly pests targeting face flies, horn flies and stable flies. The second goal of this project is the conduct an in-depth study to further our understanding of the trophic interactions of dung beetles in the pasture ecosystem and provide accessible information for farmers on dung beetle identification and ecology. Under the previous project we developed a novel walk through fly trap the removes flies from cattle as they pass through. Using vacuum action, flies on the bovine body are captured in a chamber where the insect dies soon after. The horn fly, face fly and stable fly are primary pasture pests in the US. The trap effectively removes and control horn fly but is less efficacious for face fly and stable fly. Our first task is to improve the trap efficiency for face flies and stable flies by modification to the device that targets predilection sites for these insects. This trap is most effective for managing flies on dairy cattle because of the frequency of use as cows are milked twice each day. Our second task is to develop alternative power sources to energize the trap and therefore allow it to be used on cattle on continuous grazing. The third task of this project is to conduct research on the role of dung beetles in the pasture ecosystem, examine the biotic and abiotic factors that influence dung beetle survival and their potential impacts on pasture health. We will conduct a census of dung beetle populations in NC and identify anthropogenic effects that may influence population growth and survival. Our last task is to develop web content to educate farmers, students, researchers and the general public of the role of dung beetles in the pasture ecosystem and how to conserve and propagate them.

Animal Health Component

100%

Research Effort Categories

Basic

(N/A)

Applied

100%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
216	3110	1070	100%

Knowledge Area
216 - Integrated Pest Management Systems;

Subject Of Investigation
3110 - Insects;

Field Of Science
1070 - Ecology;

Keywords

pasture fly

cattle

beef

dairy

vacuum fly trap

dung beetle

pasture ecology

Goals / Objectives
Most small farms in the United States include pastures for grazing cattle- either beef or small to moderate scale dairy. Regionally the majority of small farm acreage is devoted to pasture based livestock operations. The pasture is an economically important ecological system that functions as a complex of interactions between the sun, plants, soil and water. Specifically, the solar energy drives plant growth that grazing animals convert biomass and byproducts that contribute to nutrient cycling. Nutritionally, cattle use only about 25% of the N and P, and 15% of the K contained in forages and excrete the remaining as dung, to be returned to the soil through decomposition. Several biological processes occur during dung decomposition but insects, both pestiferous and beneficial are notable. For this project, my goal is to develop new tools for the management of pasture fly pests targeting face flies, horn flies and stable flies. The second goal of this project is the conduct an in-depth study to further our understanding of the trophic interactions of dung beetles in the pasture ecosystem and provide accessible information for farmers on dung beetle identification and ecology.The face fly, Musca autumnalis, the horn fly, Haematobia irritans and the stable fly Stomoxys calcitrans are the primary pests of pastured cattle in the United States (Bruce 1964, Drummond et al. 1988, Krafsur and Moon 1997).The face fly is the primary pest of pastured cattle from coast to coast. This fly feeds on lachrymal and mucosal secretions of the eyes and nose of cattle. The annoyance and irritation associated with its' feeding habits cause cattle to change grazing habits that often result in poor utilization of pasture. The face fly is also a carrier of a bacterium, Moraxella bovis, the causative agent of infectious bovine keratoconjunctivitis (IBK) also known as pinkeye.The horn fly is an obligate blood-sucking parasite of cattle and is considered the most important pest of pastured cattle in the US. Horn fly feeding habits cause cattle annoyance, alteration of grazing habits, and decrease both milk production and weight gains. Animals may carry as many as 10,000 flies each and because horn flies feed 10 to 12 times per day the daily blood loss is tremendous. Horn flies also have been incriminated in the transmission of bovine mastitis.Like the horn fly, the stable fly is an obligate blood feeder. These flies prefer feeding on the lower body and legs of the host, and take an average of 2-3 blood meals per day. An abundance of flies cause cattle to bunch in an attempt to avoid the painful bite. Unlike the horn fly, ovipositing stable flies prefer older dung mixed with straw, wasted hay and urine. Stable fly densities have increased in pastures where cattle are fed hay outdoors.Goal 1: Improved pasture fly management. For this goal, a uniquely designed vacuum powered walk through fly-trap was designed to remove flies from cattle as they pass through the trap (Patent Number 8,505,493 B2, Denning et al. 2014). The trap prototype was tested on a dairy at the Center for Environmental Farming Systems (CEFS) in Goldsboro NC from 2007 to 2015. Using this system, it has not been necessary to treat these cattle with an insecticide for more than 7 years. While this trap is most efficient for horn fly control, modifications to the trap are expected to increase efficiency for other flies. Secondly, dairy and beef cattle spend significant time each day on pasture land. Dairy cattle are brought to a central location for milking at least twice each day and it is there they pass through the fly trap. By developing a portable fly trap with a power supply allowing it to operate "off the grid", would significantly improve the application of this technology to beef cattle production where cattle remain on pasture continuously.Objective 1: Evaluate efficacy of the vacuum fly trap for the control of horn fly, face fly and stable fly.Objective 2: Develop a vacuum fly trap amenable to both dairy and beef cattle production.Goal 2: Dung beetle ecosystem services. Producers recognize that dung beetles provide ecological services to the pasture for their role in dung decomposition. Cattle use a portion of N, P, and K contained in forages and excrete nutrient rich dung to the soil. Many insects contribute to the biological processes of decomposition and the dung beetles are notable. Dung beetles serve the pasture ecosystem by facilitating the decomposition process and enhancing nutrient cycling therefore leading to better forage growth. Dung beetles achieve this by consuming dung and dung fluids, and by using dung to feed their young. These coprophagus beetles exhibit distinct nesting behaviors described as rollers, tunnelers and dwellers, each serving the ecosystem in a unique way. Each dung beetle type benefits the soil by increasing water absorption, introducing organic matter into the soil, and reducing non-point sources of organic pollution. In addition to dung beetles other biotic factors include the cattle, plants and soil micro and macro organisms. The interactions of these components within the pasture ecosystem is not clearly understood. Because significant events and interactions occur below ground, few producers are aware of these activities. Goal two is designed to explore these interactions and provide information to farmers and producers on the identification and biology of dung beetles and the interactions of the biotic and abiotic components of the pasture ecosystem.Objective 3: Identify, define and evaluate the role of dung beetles as key contributors to the pasture ecosystem.Objective 4. Conduct a census survey of dung beetle populations within the state with the goal of determining population densities and species richness.Objective 5: Develop a questionnaire to determine the environmental and anthropogenic factors effecting dung beetle populations.Objective 6. Develop e-based extension documents for the identification of dung beetles, dung beetle movies, biology and their conservation.

Project Methods
Objective 1. Evaluate efficacy of the vacuum fly trap for the control of horn fly, face fly and stable fly. For this study, a uniquely designed vacuum powered walk through fly-trap was designed to remove flies from cattle as they pass through the trap (Patent Number 8,505,493 B2, Denning et al. 2014 J. Dairy Sci.). The trap prototype was tested at the Center for Environmental Farming Systems (CEFS) in Goldsboro NC from 2007 to 2015. Using this system, it has not been necessary to treat these cattle with an insecticide for more than 7 years. While this trap is most efficient for horn fly control, modifications to the trap are expected to increase efficiency for other flies.Weekly pasture fly densities per animal will be assessed by estimating the total number of flies on 10 randomly selected animals in the treatment herds. A second group of animals, not allowed to pass through the device, will be used as the untreated controls. Two research herds serving as trap sites are located at the Center for Environmental Farming Systems, Goldsboro, NC. Additional herds have been identified from the Piedmont region of NC if needed. Each will have a vacuum fly trap dedicated for each herd use. In addition to counting the flies on the animals, we will quantify the number of flies captured by the traps each week by removing the collection container and cold chilling the flies to immobilize. If fly densities are high, containers may fill up, requiring twice weekly replacement. Flies will be transferred to plastic bags and frozen, then air-dried and weighed. The total number of flies captured per week will be calculated by extrapolation from subsamples sorted to species. A separate dairy farm will serve as the conventional fly control program reliant on insecticides registered for use on dairy cattle, for example the synthetic pyrethroid cyfluthrin. We chose the pour-on treatment because the labor involved in applying the treatments to the cattle is similar to that required of the walk-through fly trap. Cattle will be treated monthly. Fly densities will be monitored weekly following the methods described above. We will request each farm set aside 8 cull steers for untreated controls to monitor insect populations regionally.Objective 2 Develop a vacuum fly trap amenable to both dairy and beef production.Dairy and beef cattle spend significant time each day on pasture land but only dairy cattle come into a parlor to be milked. To increase the utility of this effective fly trap, we plan to adapt the trap to alternate power sources. We will place emphasis on gasoline powered generators as a power source because it meets the power demands of the device. Additional modifications may include durable but light weight ultrastructure and mobility. Light weight and mobile equipment has greatest appeal for cattle producers. Under this objective we will also determine the optimal frequency of use to maximize fly control.At least 60 cows will be trained to use the walk through fly trap. Cows will pass through the trap at least once each day to remove the flies. A control group of similar size will not use the trap. A trained observer will estimate the number of flies weekly on 20 randomly selected cows within the larger group. Counts will be made from a distance of approximately 3 meters or less. The number of flies will be recorded for each animal and the group means and standard error calculated for treatment analysis. The number of flies captured in the trap will be sorted to species and counted for comparison to visual counts on individual animals.Analysis of data from objectives 1 and 2 will be performed using SAS ANOVA and Tukey's means separation.Objective 3: Identify, define and evaluate the role of dung beetles as key contributors to the pasture ecosystem. Using wild caught dung beetles from the selected farms we will conduct experiments to determine the impact of soil moisture on dung beetle survival and emergence in North Carolina Piedmont and Coastal Plain cattle systems. There are several abiotic factors that influence beetle survival and activity; rain events, temperature and soil compaction. We will conduct simultaneous field and lab studies to investigate conditions can lead alter normal dung beetle survival. Known to dry hard and compact, NC Cecil red clay may inhibit beetle emergence. Up to 4 times each year, prior to a grazing rotational cycle trained team members will visually assess the botanical composition of each pasture.Objective 4. Conduct a census survey of dung beetle populations within the state with the goal of determining population densities and species richness. Using pit fall traps dung beetles will be surveyed from 4 locations within the geographic regions of North Carolina, coastal plain, piedmont and mountains. Beetle census taking will occur to coincide with activity records identified by Bertone et al. 2005, likely spring, summer and fall when beetles were most active. Collected insects will be identified to species and relative abundance determined.Objective 5: Develop a questionnaire to determine the environmental and anthropogenic factors effecting dung beetle populations. For all participant farms in this study we will develop a questionnaire to identify environmental (soil type, rainfall, elevation, temperatures etc.) and anthropogenic factors (pesticide use, frequency of rotation, husbandry practices etc.). This questionnaire will not contain information linked to the land owner or property, however assurances under full institutional review board standards will be reviewed. Background climatological data will be gathered from the NC Climate center. If necessary, soil information may be obtained from the NC Dept. of Agriculture soils testing lab, Raleigh, NC.Objective 6. Develop e-based extension documents for the identification of dung beetles, dung beetle movies, biology and their conservation. Living insects will be collected for occasional web content development projects. Video clips will be generated using AV equipment in the Dept. of Entomology for use on web pages. High quality digital images will be developed for plant and insect identification. Keys will be developed to accompany images to make the process simple for the user. Additional information on the ecology of pasture systems through Crop Science extension programs, such as the common and useful guides to improve pasture health. Links to animal science extension programs will be provided.

Progress 10/01/15 to 09/30/20

Outputs
Target Audience:Conventional and organic dairy and beef producers, grazers, 4-H groups, youth groups, county extension agents, students, teachers, researchers, extension specialists, environmentalists and conservationists. This topic appeals to Museum of Natural History staff and researchers, conservation groups, citizen science groups, news media and Natural Resource and Conservation Service personnel. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Goal 1: Improved pasture fly management Objective 1. Evaluate the efficacy of the vacuum fly trap for the control of horn fly, face fly and stable fly. The fly trap was originally designed for use in dairy systems because the cattle come into a central location to be milked 2 or 3 times each day. Placing the trap in a central location that has an electrical power supply is most efficient. The electric motor in the trap pulls air and flies off the back and belly of cattle to trap them within a filtered chamber. The exhausted air assists in the disturbance of the flies making them vulnerable to the vacuum intake ports. By redirecting a portion of the exhausted air to blow across the cows face, dislodging the face flies and forcing them into an opposing trap chamber. The opening to the chamber was a screened funnel that remained open while under air pressure, but collapsed when the trap was not in use, thus trapping the flies inside. The flies died before the next use. The modifications to the trap effectively increased the number of face flies removed from the cattle. The modification removed flies from the head and face of the cows passing through during a single morning milking of 150 cows. Flies captured in the chamber were predominately face flies (60%), horn flies (30%), stable flies (4%) and house flies (6%) respectively.The season long impact of the face fly modification to the trap has not been evaluated but shows promise. Objective 2. Modify the fly trap for use with beef cattle. Dairy and beef cattle spend significant time each day on pasture land but only dairy cattle come into a parlor to be milked. To increase the utility of this flytrap, we adapted the power source from electricity to propane. By adding a 6.5 horsepower propane engine with a 12 volt battery powered electric starter, we developed a versatile flytrap that can be used in remote locations. To detect the presence of an animal, tilt switches were located at the entry and exit of the trap. When the switch signal indicated an animal had entered the trap an Arduino microprocessor initiated the engine start, a 3 minute run and stall processes. The cattle had free access to a pasture and a shaded structure to avoid the sun. The flytrap was placed at the entrance to the shaded area, which also served as the grain feeding site. Cattle used the walk through flytrap at least once a day by offering grain.Once the grain was consumed, the cattle freely returned to the pasture to graze and/or return to the shade area. A pretreatment control group of similar size did not use the trap. The pretreatment fly count was above 250 fly average. The number of flies captured in the trap were collected weekly, sorted to species and counted for comparison. The number of horn flies was reduced 91% within 6 weeks. The trap removed 71,943 flies from the cattle, of which 67,930 were horn flies, 2817 stable flies, 349 face flies, and 847 house flies. Goal 2. Dung beetle ecosystem services Objective 3: Identify, define and evaluate the role of dung beetles as key contributors to the pasture ecosystem. There exists a sufficient body of literature on the benefits of dung beetles in the pasture ecosystem. These include but are not limited to nutrient recycling, turnover of soil to improve soil texture and improved aggregate, incorporation of organic matter into OM limited soils and increased soil percolation by tunneling into soils and allowing greater penetration of water to subsurface root structures. At the surface level, dung beetle reduce pasture fouling by the prompt removal of dung covering pasture grasses and thereby increasing the availability of forages for use by livestock and wildlife. Pesticide use remains a major limiting factor to establishing populations of dung beetles in pastures. Reducing the use frequency of macrocyclic lactone insecticides serves to limit the negative impacts on beetles. Collaboration with UNCG Do dung endophytes influence the colonization of dung by beetles? Dr. Tatsiana Shymanovich, University of North Carolina Greensboro and North Carolina State University, developed a project to investigate endophytes common in tall fescue cultivar, Kentucky 31, that produce bioactive compounds including the ergot alkaloid, ergovaline, with known toxicity to cattle and insects. In Dr. Shymanovich's study novel cultivars, BarOptima PLUS E34, Jesup MaxQ, and Texoma MaxQ II, each possess different endophyte strains that are non-toxic to cattle but still protect against insect herbivory. Our study investigated if different cultivars have different effects on dung beetles, and determined if ergovaline could be detected in cow dung. Ergovaline at 0.04 and 0.27 μg/g was detected only from Kentucky 31 dung samples from 2017 and 2018 collections, respectively. We compared the oviposition preferences, larval development and survival of Onthophagus taurus and Digonthophagus gazelle when reared on dung from each cultivar versus dung from a endophyte free pasture. Among the four cultivars, for making brood-balls O. taurus preferred dung from Texoma MaxQ II while Kentucky 31 and BarOptima PLUS E34 were avoided. Both beetle species preferred dung from Texoma MaxQ II versus Kentucky 31 pasture. Larval survival was not affected by dung-type with the 2017 samples but both species had reduced survival on Kentucky 31 in 2018. Development time for O. taurus was shorter on dung collected from Texoma MaxQ II versus Kentucky 31 or uninfected dung brood-balls. Adult mass was not affected in the 2017 collection but was reduced in 2018 Kentucky 31 samples when compared with Texoma MaxQ II. Dung beetles can differentiate dung from pastures with different tall fescue cultivars. The novel cultivar, Texoma MaxQ II, provides morebenefits for dung beetles. Pasture renovations with Texoma MaxQ II may improve pasture ecology by enhancing dung beetle populations. Objective 4. Conduct a census survey of dung beetle populations within the state with the goal of determining population densities and species richness.Using pit fall traps dung beetles we surveyed from 12 locations within the geographic regions of North Carolina, coastal plain, piedmont and mountains. Beetle census taking will occur to coincide with activity records identified by Bertone et al. 2005, likely spring, summer and fall when beetles were most active. Collected insects wereidentified to species and relative abundance determined. Objective 5: Develop a questionnaire to determine the environmental and anthropogenic factors effecting dung beetle populations. In the last 10 years producers have become aware of the importance of dung beetles in their pastures and the benefits dung beetles provide in the sustainability of the pasture system. There is nothing to report here.As indicated in the table 1, many of the Aphodini beetles were revised and placed in different genera (Gordon and Shelley 2007). The list of beetles here reflect that revision for the genus Aphodius. A total of 17 species of beetles were collected from Chatham, Rockingham, Wake, Wayne, Nash, Chowan, Pender, Avery, Catawba, Union, Buncombe and Clay counties from 2015. Of these Onthophagus taurus was most abundant making up 59% of the total 13,379 specimens. This tunneling beetle was most abundant in the 2005 collections of Bertone et al. 2005. The second most abundant beetles was Labarrus pseudolividus, making up 26% of the collection. Objective 6. Develop e-based extension documents for the identification of dung beetles, dung beetle movies, biology and their conservation. Extension products developed follow: Website Links: https://cefs.ncsu.edu/resources/dung-beetles-of-cerntral-and-eastern-north-carolina-cattle-pastures/ NRCS Pastureland Ecology Annual Workshop. June 2016, 2017, 2018, 2019. Not held in 2020 due to pandemic. In total 15 presentations were were made to 564 individuals, farmers and allied industriesin 8 counties.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Fowler, F., Wilcox, T., Orr, S. and Watson, W., 2020. Sampling efficacy and survival rates of Labarrus pseudolividus (Coleoptera: Scarabaeidae) and Onthophagus taurus (Coleoptera: Scarabaeidae) using flotation and sieve-separation methodology. Journal of Insect Science, 20(6), p.18.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Fowler, F., Denning, S., Hu, S. and Watson, W., 2020. Carbon Neutral: The Failure of Dung Beetles (Coleoptera: Scarabaeidae) to Affect Dung-Generated Greenhouse Gases in the Pasture. Environmental entomology, 49(5), pp.1105-1116.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Shymanovich, T., Crowley, G., Ingram, S., Steen, C., Panaccione, D.G., Young, C.A., Watson, W. and Poore, M., 2020. Endophytes matter: Variation of dung beetle performance across different endophyte-infected tall fescue cultivars. Applied Soil Ecology, 152, p.103561.
• Type: Journal Articles Status: Published Year Published: 2020 Citation: Smythe, B., Boxler, D., Brewer, G., Psota, E. and Watson, D.W., 2020. Using visual and digital imagery to quantify horn fly (Diptera: Muscidae) densities. Journal of Insect Science, 20(6), p.16.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Fisher, M.L., Fowler, F.E., Denning, S.S. and Watson, D.W., 2017. Survival of the house fly (Diptera: Muscidae) on Truvia and other sweeteners. Journal of Medical Entomology, 54(4), pp.999-1005.
• Type: Journal Articles Status: Published Year Published: 2017 Citation: Mullens, B.A., Watson, D.W., Gerry, A.C., Sandelin, B.A., Soto, D., Rawls, D., Denning, S., Guisewite, L. and Cammack, J., 2017. Field trials of fatty acids and geraniol applied to cattle for suppression of horn flies, Haematobia irritans (Diptera: Muscidae), with observations on fly defensive behaviors. Veterinary parasitology, 245, pp.14-28.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Deguenon, J.M., Travanty, N., Zhu, J., Carr, A., Denning, S., Reiskind, M.H., Watson, D.W., Roe, R.M. and Ponnusamy, L., 2019. Exogenous and endogenous microbiomes of wild-caught Phormia regina (Diptera: Calliphoridae) flies from a suburban farm by 16S rRNA gene sequencing. Scientific reports, 9(1), pp.1-13.
• Type: Journal Articles Status: Published Year Published: 2019 Citation: Deguenon, J.M., Zhu, J., Denning, S., Reiskind, M.H., Watson, D.W. and Roe, R.M., 2019. Control of Filth Flies, Cochliomyia macellaria (Diptera: Calliphoridae), Musca domestica (Diptera: Muscidae), and Sarcophaga bullata (Diptera: Sarcophagidae), Using Novel Plant-Derived Methyl Ketones. Journal of Medical Entomology, 56(6), pp.1704-1714.
• Type: Book Chapters Status: Published Year Published: 2020 Citation: de Le�n, A.A.P., Mitchell, R.D. and Watson, D.W., 2020. Ectoparasites of cattle. Veterinary Clinics: Food Animal Practice, 36(1), pp.173-185.
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Shymanovich, T., G. Crowley, S. Ingram, C. Steen, D. Panaccione, C. Young, and W. Watson. 2020. Effects of tall fescue cultivars on dung beetle performance. Poster Presentation, Entomol. Soc. America. Virtual Annual Meeting.

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Researchers, Entomologists, Veterinarians, Producers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest?Progress reports on this project were presented at professional meetings and in extension outreach events. What do you plan to do during the next reporting period to accomplish the goals?Continue to conduct testing of the fly trap for efficacy agains face flies and stable flies and dispersal distances as measured with the flight mill devices. Plans to conduct the dung beetle survey of the state of NC and the anthroprogenic impacts on dung beetle populations.

Impacts
What was accomplished under these goals? We have established colonies of target insects including face flies, flesh flies and blow flies. We have established contacts and are receiving horn flies and stable flies from USDA collaborators. We created modifications to the vacuum powered fly trap to enhance collections of under represented pest flies, the stable fly and the face fly. The evaluation of these modifications is currently underway using traps on dairies. Additional tests will be conducted to retrofit the traps for use in beef cattle pastures. We have conducted research on the ecosystem services provided by dung beetles in the pasture. Onthophagus taurus is the most abundant beetle common in NC pastures. Presumably the activity of this beetle increased aeration of dung resulting the shift from anaerobic to aerobic microbial communities, resulting in the reduction of greenhouse gas emissions.We demonstrated the in situ testing of the impact of dung beetles on gas emission was required to measure true effects and laboratory testing with artifically mixed dung did not produce a testable model.

Publications

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:Livestock producers, farmers, scientists, researchers, general public and state and federal government Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?NRCS Pasture Land Ecology Course. Presented on pasture fly management and conservation biology of dung beetles. How have the results been disseminated to communities of interest?Information has been disseminated at scientific meetings, Livestock Insect Workers Conference and the Entomological Society of America National meeting. What do you plan to do during the next reporting period to accomplish the goals?Complete the extension documents on dung beetle ecology and pasture fly management

Impacts
What was accomplished under these goals? Maintaining healthy ecosystems while improving food production is the challenge of the century, and a potential route is nutrient recycling. When microbes decompose dung, they volatilize the available carbon (C) and nitrogen (N) into greenhouse gases (GHGs) including carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O), instead of storing that C and N in the soil for plants. Dung beetles promote rapid decomposition by aerating and mixing the dung - thereby lowering GHGs while increasing soil C and N. Recent studies, however, show that most dung beetles do not reduce, and may even contribute, to the total GHGs. Mimicking those studies' additive designs, I compared the GHG production of dung beetles to mixed dung controls, but I additionally controlled for dung mixing. My results show there were no differences between dung beetles and homogenized dung for any GHG, but showed a significant 43%, 55%, and 87% reduction of CO2, CH4, or N2O, respectively, when comparing mixed dung to unmixed dung. This shows that mixing, or homogenizing/standardizing, the dung permanently changes it such that premixed dung does not reflect natural conditions. In other words, premixing dung before adding dung beetles steals the dung beetles' own chance to reduce GHGs themselves. Dung beetles, therefore, are likely reducing total GHGs much more than previously thought. My findings are relevant to all microbiologists as they show that homogenizing substrates inhabited by aerobes and anaerobes may confound experiments, and one must control for homogenization to know if there is a confounding effect.

Publications

• Type: Conference Papers and Presentations Status: Other Year Published: 2017 Citation: Fowler, Fallon, S. Denning, S. Hu, and Wes Watson, 2017. The dung diaries: How different beetle groups affect dung-mediated greenhouse gas production. Ent. Soc. America. Denver Co. Nov. 5-8

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Conventional and organic cattle and dairy producers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Experimental results were presented at regional and national meetings by students. Fowler et al. 2016. How different beetle groups affect dung mediated greehouse gas production. NC Entomological Society Annual Conference. Malone et al. 2016. Changing pat size and monitoring face flylarval movement and survial. NCSU Undergraduate Symposium. How have the results been disseminated to communities of interest?Results have been incorporated into extension meetings throughout the state. Watson, D. W.. 2015. Northeast Pasture Consortium Annual Conference. Dung Beetle contributions to pasture nutrient cycling. March 12, 2015. Morgantown, WV. Watson, D. W., 2015. Maximizing dung beetle conservation. Northeast Pasture Consortium Annual Conference. March 12, 2015. Morgantown, WV. Watson, D. W. 2015. Pest Management for Cattle: Old issues and new technology. Guilford Co. Cattleman's association. August 18, 2015. Watson, D. W. 2015. Ectoparasites of cattle and their control. Rockingham Co. Cattleman's association. April 9, 2015. Watson, D. W. 2015. Controlling extoparsites on cattle. Clinton Cattleman's Association. January 27, 2015 Watson, D. W. 2015. Ticks and tick borne disease in NC. Rockingham Co. Extension Service. May 27, 2015. Watson, D. W. 2016. Pest Management for Cattle: Old issues and new technology. Burlington, NC Cattleman's association. February 9 2016 Watson, D. W. 2016. Ectoparasites of cattle and their control. Person Co. Cattleman's association. March 21, 2016. Watson, D. W. 2016. What can we learn from a fly? State Bureau of Investigation, Hunt Lib. May 12, 2016 Watson, D. W. 2016. Management of pests in the US poultry industry. International Poultry Conf. Raleigh, NC. Hosted by the Prestage Department of Poultry Science. May 17, 2016 Watson, D. W. 2016. Managing beneficial insects and pests in the pasture ecosystem. Goldsboro, NC. NRCS Workshop, June 15, 2016. Watson, D. W. 2016. Pest Management Issues for Turkey Production. Poultry Federation, New Bern, NC. June 21, 2016 Watson, D. W. 2016. Pasture Fly Management. Beef Cattle Field Days. Goldsboro, NC. July 23, 2016. . What do you plan to do during the next reporting period to accomplish the goals?We are developing protocols to evaluate modifications to the cow vac this upcoming fly season. We have developed protocols for the mark and recapture of horn flies to better understand fly dispersal. We have entered into season two of the dung beetle project evaluating the impact of these insects on greenhouse gas emissions from dung.

Impacts
What was accomplished under these goals? This project has two main goals, improve on the cow vac system and expand our knowledge of dung beetle ecology. The cow-vac system provides horn fly control for pasture based dairy systems. Placed in the alleyway, the trap pulls a vacuum as the animal passes through. Horn flies dislodged from the animal are readily vacuumed up and are retained inside the trap. Using the trap twice daily effectively removes sufficient numbers of flies to reduce the breeding population and provide relief for the cattle and dairy workers. In addition to the horn fly, the trap captures the face fly and the stable fly but in lower numbers. For objective 1, we are working on modifications to the trap to enhance the capture rate for face fly and stable fly. Face flies tend to take flight before the cattle enter the trap. Taking advantage of this behavioral trait, we recognized that by redirecting the ductwork for the exhaust air we were able to blow the face flies into a capture net. We are developing protocols to evaluate the modification this upcoming fly season. The cow-vac system is currently limited by the availability of electrical power. We are designing portable power supplies sufficient to power the trap for both pasture based dairy and beef cattle. Currently solar systems are too underpowered to drive the vacuum system. A portable generator is sufficient to drive the system, but it requires refueling and protection from the cattle that may attempt to rub or damage the equipment. Dung beetles are known to provide a variety of ecosystem services, removal of dung, reduction of dung associated pests, improved nutrient cycling and enhance soil percolation. My graduate student received a fellowship to study the role of dung beetle behaviors and activities in the mitigation of greenhouse gasses. By disrupting the dung pat and burying dung in the soil, dung beetles reduce NO2, CO2 and Methane, all known to be emitted from cattle dung.

Publications