Integrated Pest Management for Fly Control in Maine Dairy Barns

Bulletin #5002

Noticed a Few Flies Around?

A silly question, perhaps, about a serious issue. Flies around the barn and milking parlor are a nuisance to the cows and to us. How can we manage the level of flies in our dairy operations? A multipronged approach, called Integrated Pest Management (IPM), is the key.

The first step in every IPM Economic problems caused by program is to learn about the pests high house fly populations in that are causing the problem. On dairy operations: dairy farms, the primary fly perpetrators are the housefly and the stable fly. • Reduced milk production: cows The housefly (Musca domestica) must expend extra energy fending off flies is the most common and costly fly pest. The life cycle of the housefly • Reduced farm worker can be completed in 10 days during productivity: flies interfere with warm weather. The female adult work such as feeding and milking lays her eggs in manure, decaying • Increased frequency of animal silage, spilled feed, soiled bedding disease transmission, leading to and other organic matter. After a - increased medication costs, day or more, each egg hatches into and a white maggot (larva) that feeds for approximately four to six days - increased veterinary service costs before transforming into a brown cigar-shaped pupa. In a few more • Increased risk of complaints and days, an adult fly will emerge to legal action from the public mate and start the next generation. • Increased potential for spread of Since each female housefly lays human diseases 150-200 eggs, and one pound of manure can contain more than 1,500 Source: Douglass E. Stevenson and Jesse maggots, it is important to take Cocke, Integrated pest management of flies in Texas dairies, Texas Agricultural Extension steps to break the life cycle. Service, 4. Stable flies (Stomoxys calcitrans) Cultural Control are similar in appearance and The biggest part of cultural fly lifestyle to houseflies, with one control is sanitation. Good important distinction—they bite! sanitation is the most practical and Like the housefly, the stable fly economical way to manage fly enjoys a moist, decaying environment. populations. It’s best to begin before Since this is a blood-feeding fly, its the flies have had a chance to economic impact can be large. Stable develop into large populations. fly populations can lower milk Stable fly production by 15 to 30 percent! Think clean and dry: • Clean out calf hutches and How Do You Control Flies? holding pens on a regular basis and keep them ventilated. Move Develop a plan: portable hutches on a regular 1. Determine current levels of fly basis and elevate one of the sides populations: for instance, you to provide extra ventilation if could put up fly strips and record necessary. Calf areas are prime the frequency with which they need spots for fly breeding. replacing. You need to know your • Keep open feeding lanes and the starting point in order to track concrete corners of the feeding your progress. bins clean. 2. Identify an achievable goal: decide • Completely clean the entrance the level of flies you can live with and exit lanes of the milking (for instance, a low enough parlor daily, or after each milking. population level that strips only Good need replacing once a week). • In liquid manure pits, prevent sanitation is 3. Map out a way to get there: floating mats by collecting debris from the runoff collection the most develop an IPM plan for keeping channels, sediment basins and practical and fly populations below unacceptable retention ponds. economical levels. Your plan should include a way to variety of control strategies, • Get out your weed whacker and manage fly including cultural, biological, mower! Keep the entrance and chemical and physical controls. exit walkway corners weed-free populations. and trimmed to allow weekly 4. Act early! Fly populations start cleanup of collected manure. building when the weather warms Keep vegetation around barns, up, so begin your fly control feeders, hutches, and manure program in early spring. piles mowed to eliminate fly 5. Track and evaluate your progress. resting areas. Use sticky tapes or speck cards to • Remove small piles of manure monitor fly activity in and around and spread out straw as barns and the milking parlor. Keep frequently as possible. records of how fast they fill up. Record any control actions you • Dispose of mortalities and take, and when they were taken. afterbirth immediately. Evaluate what worked and why.

2 Integrated Pest Management for Fly Control in Maine Dairy Barns • Keep animal areas as dry as Biological Control possible. Scrape out manure Nature can help in the battle regularly, and provide a three to against flies by providing natural four percent slope to allow enemies. These include predatory drainage of liquid from stalls. beetles and mites, parasitic wasps, and fly pathogens. You can promote • Clean hard to reach areas such as natural enemies by keeping facilities behind waterers, in corners and clean and dry and limiting pesticide under pen partitions. use. • Clean the manure spreader when Predators: Hister beetles occur are Housefly maggot not in use: it’s an ideal place for found primarily in older manure flies to breed and be transported. packs. These small, black, shiny beetles consume up to fly 24 eggs a • Keep areas around feed storage, day. Predatory mites also feed on feed bunks and watering tanks housefly eggs as well as small free from moisture and manure. Fix water leaks promptly. maggots. • Move your round bale feeder regularly to prevent manure, urine, and hay buildup. • Keep flies out of milk rooms by Tips for using parasites: maintaining window screens (use 14-16 mesh) and keeping doors If using parasites, find a reputable closed whenever possible. supplier, and ask specifically for Northeast-adapted strains. Research and Remember: clean and dry. experience have shown that the wasp species Muscidfurax raptor is most effective in northeastern dairy operations.

Follow the directions provided by the supplier. Ask questions of your supplier to ensure that you are getting a high quality and suitable product shipped and delivered in a timely and dependable manner.

Don’t forget that these are living organisms—make sure the package isn’t left in the heat or cold—and release the wasps as soon as possible. It is best to begin releases in the early spring to establish the species and get a head start on the fly population. Parasites perform best in enclosed environments like calf hutches; their benefit is less noticeable in open environments.

University of Maine Cooperative Extension 3 Parasites: Parasitic wasps look from plant materials. Contact Maine like tiny gnats. Although they are Organic Farmers and Gardeners harmless to humans and cattle and Association (MOFGA)** for go unnoticed in dairy operations, information. Before using any spray they effectively find and kill fly on an organic farm, contact both pupae. The life cycle of most wasps MOFGA and the Board of Pesticide Before using is about three weeks long. There are Control. any chemical, wasps commercially available for always release to augment the natural Physical Control check with populations that exist. Tapes, traps, and lights are forms When using biological control, of physical control aimed at attracting the Maine remember that it is only one piece of and killing the adult fly. These can Board of a complete fly management program be very useful as part of an integrated Pesticide and, like many other components, pest management system. Use traps Control* to will not get rid of flies entirely when in areas where the use of chemicals see if it is used alone. Integrated pest is difficult, ineffective or unacceptable, management is a multimethod such as milking parlors, milk registered approach. holding rooms, and feed holding for use in and mixing areas. Be sure to keep this state Chemical Control physical controls maintained for and what If you are using biological control maximum effect. regulations methods, be aware that parasitic wasps and other “good bugs” are The IPM Strategy pertain to its often less resistant to insecticides use. than flies. Use chemicals that are Integrated pest management is a compatible with biological control management strategy incorporating methods, or you may end up killing a number of control methods that fewer flies and more of their enemies! complement one another and work There are a wide variety of together. By using cultural control, chemicals to control flies. Before biological control, chemical control using any chemical, always check and physical control as pieces of a with the Maine Board of Pesticide complete plan, you can Control* to see if it is registered for economically and effectively use in this state and what regulations manage fly populations. pertain to its use. Always follow the label’s instructions. There are chemical controls for organic producers too. These Parasitic wasp on chemicals, such as pyrethrins and fly pupa citric acid, are naturally derived

* Maine Board of Pesticide Control: Augusta 207-287-2731; Presque Isle 207-764-2039 TDD: 207-287-4470 ** Maine Organic Farmers and Gardeners Association: 207-548-4142

4 Integrated Pest Management for Fly Control in Maine Dairy Barns Here are seven principles to aid 4. Use fly weaknesses to your you in decision-making: advantage. Flies are hard to 1. Plan a strategy. Set an attainable control because they have a short goal, make a plan that employs generation time, are prolific, and more than one method to control can detoxify many poisons. But flies, implement it, measure your habitat changes make them more progress, and keep it simple and susceptible to natural control flexible. Also, have a contingency factors. By keeping the barn clean plan if setbacks occur. and dry, you can increase the generation time and lower their 2. An ounce of prevention is worth a reproductivity. Careful use of pound of cure. Start before the insecticides will help flies do! Begin your plan of action minimize resistance to before fly populations begin to pesticides and protect build. When warm weather arrives, natural enemies. By using a monitor fly activity, adjust to new variety of control strategies in an situations like changes in weather, integrated program, you can don’t repeat what doesn't work, attack fly weaknesses on multiple and keep up your efforts through levels. the whole season. 5. Make sure the pieces of your plan 3. Use what you need to get the job work together. done. If using pesticides, follow the label instructions and avoid For more information about fly unnecessary applications. Be control, contact your local Cooperative decisive and take the necessary Extension office. actions.

Prepared by Patricia Westenbroek, Extension integrated farm educator

Special thanks to Kathy Murray, IPM entomologist, Maine Department of Agriculture, Food and Rural Resources, for her role as peer reviewer of this fact sheet.

This fact sheet was adapted from the following publications:

Rutz, Donald A., Christopher J. Geden and Charles W. Pitts. Pest Management Recommendations for Dairy Cattle. New York: Cornell and Penn State Cooperative Extension. Retrieved from the World Wide Web March 22, 2002 at .

Rutz, Donald A., D. Wes Watson and J. Keith Waldron. Integrated Management of Flies in and around Dairy and Livestock Barns. New York State Integrated Pest Management Program, Cornell Cooperative Extension. Retrieved from the World Wide Web March 22, 2002 at http://www.nysipm.cornell.edu/factsheets/dairy/barnflies/barnflies/html>.

Stevenson, Douglass E. and Jesse Cocke. Integrated pest management of flies in Texas dairies. Texas Agricultural Extension Service. Retrieved from the World Wide Web March 22, 2002 at .

University of Maine Cooperative Extension 5 For the most current Extension publications, see our online catalog at: www.umext.maine.edu

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6 Integrated Pest Management for Fly Control in Maine Dairy Barns