Can dung beetles help my pasture ecosystem? What are the signs that they are present and how can I encourage populations throughout my pastures?
Answer: Dung beetles belong to the zoological order Coleoptera and family Scarabaeidae and there are over 90 species in the United States. Dung Beetles can help improve your pasture system in several ways. They play a small but remarkable role in the pasture ecosystem. They feed on manure, use it to provide housing and food for their young, and improve nutrient cycling, soil structure, and forage growth in the meantime. Dung beetles are important enough in manure and nutrient recycling that they well deserve the pasture manager’s attention.Dung beetle benefits to livestock and the pasture environment just might outweigh their somewhat disgusting choice of food. For example, manure is the breeding ground and incubator for horn flies and face flies, two economically important pests of cattle. As dung beetles feed, they compete with the fly larvae for food and physically damage the flies’ eggs. Fly populations have been shown to decrease significantly in areas with dung beetle activity. Dung beetles are also reported to be effective biological control agents for gastrointestinal parasites of livestock. The eggs of most gastrointestinal parasites pass out in the feces of the host. The eggs then hatch into free-living larvae and develop into the infective stage. They then migrate onto grass, where they can be ingested by grazing animals, and complete their life cycle within the animal. If the manure/egg incubator is removed by beetles, the eggs perish and the life cycle of the parasite is broken.On a pasture-management level, dung pat removal is beneficial for forage availability. Most ruminants will not graze closely to their own species’ manure pats. Research has shown that the forage is palatable but avoided because of the dung pile. Consequently, cattle manure deposits can make from 5% to 10% per acre per year unavailable. By completely and quickly removing the manure, dung beetles can significantly enhance grazing efficiency.The tunneling behavior of dung beetles increases the soil’s capacity to absorb and hold water, and their dung-handling activities enhance soil nutrient cycling. An adequate population and mix of species can remove a complete dung pile from the surface within 24 hours.There are several things you can do as a producer to encourage the presence of Dung Beetles. Dung beetle larvae are susceptible to some insecticides used for fly and internal parasite control for cattle, especially Ivermectin. Discontinuing the use of this type of insecticide will help increase your population of dung beetles. Backrubbers, ear tags, and the occasional use of insecticide dusts and sprays are alternatives that have little or no effect on dung beetles. Another option is to treat cattle during the coolest months of the year, as the beetles and larvae are inactive at those times. Better yet, before treating your animals for internal parasites, take a fecal sample to your veterinarian. An egg count can help determine parasite load and whether the symptoms you may be seeing in the form of low gains, weight loss, unthriftiness, etc., are truly being caused by parasites.Controlled grazing systems increase dung beetle populations and varieties by concentrating the manure in smaller areas, thus reducing the time beetles must spend in search of food. Watch the length of time it takes for the manure pats to disappear in your pasture. If they remain intact for more than a few days, chances are your dung beetle population is low to non-existent. Look for hole formation in the surface of the manure pats. Many types of beetle and other insects also help to desiccate the pats. Management is the key to increasing the number and variety of dung beetles and other beneficial insects.For more information on the benefits of dung beetles and pasture management, refer to ATTRA publication Dung Beetle Benefits in the Pasture Ecosystem at https://attra.ncat.org/attra-pub/viewhtml.php?id=241.