Dung Beetles Important to Pasture Ecosystems

Important contributions to cleaner pastures are made by dung beetles

Dung beetles feed on manure, use it to provide housing and food for their young, and improve nutrient cycling, soil structure, and forage growth in the cattle feeding areas.They are important enough in manure and nutrient recycling that they well deserve the pasture manager’s attention.

Adult dung beetles are drawn to manure by odor. Many are species-specific in that they prefer a certain type of animal manure. They will fly up to ten miles in search of just the right dung, and can attack dung pats within seconds after they drop. Some species will even hitch a ride near the tails of animals in anticipation of a deposit. Once drawn by the odor, the adults use the liquid contents of the manure ("dung slurpie") for their nourishment.

• Soil moisture level is crucial to many species dung beetles, as breeding and dung burial are decreased in dry periods.
• During dry weather, the young adults emerge from the brood ball but they remain within the soil, waiting for rain.
• As with most beetles, activity decreases during the coldest months.
• The larvae remain viable deep within the soil, waiting for environmental cues such as rainfall and temperature to prompt their emergence.
• There are other dung beetle species which prefer an arid climate.
• Euoniticellus intermedius, imported from Australia, is found in south, central, and west Texas where it is especially important ecologically, being active during dry weather when other native beetles are inactive.

Improving efficiency by importing new species

• Research has been directed at importing and introducing dung beetle species that would complement and not compete with native populations, to help balance U.S. pasture ecosystems.
• The beetles in the U.S. have not been able to keep up with our increased livestock production and manure waste.
• Increased fertilizer use and higher-producing forage varieties have boosted forage yields, increasing in turn the animal carrying capacity per unit of pasture.
• Also, widespread use of insecticides, herbicides, fungicides, and anthelmintics are believed to be responsible for reducing native dung beetle populations.

A complex system of dung beetles can provide twenty-four hour action

If pastures throughout the variety of climates, soil types, and other physical conditions in the U.S. utilize the ideal complex of dung beetles, manure burial would be ongoing 24 hours a day.

Although it may take up to 120 different species of dung beetles to accomplish such a goal, the behavioral diversity among species makes it a feasible goal. Some are nighttime flyers, some fly during the day, and some prefer older manure to very fresh. If several species are working together, some may bury the brood ball close to the manure pat, some farther away, some shallow, and some deep.

Other benefits by dung beetles to the pasture system

Dung beetles’ benefits to livestock and the pasture environment just might outweigh their somewhat perceived disgusting choice of food. For example, manure is the breeding ground and incubator for horn flies (Haematobia irritans) and face flies (Musca autumnalis), two economically important pests of cattle.

A single manure pat can generate 60-80 horn fly adults if protected from insect predators and competitors; such as, dung beetles. 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. Researchers have found that 95% fewer horn flies emerged from cowpats attacked by Onthophagus gazella than from pats where beetles were excluded.

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 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.
• As the adult dung beetles use the liquid component for nourishment and the roughage for the brood balls, the dung pat quickly disappears.
• If left on the surface, up to 80% of manure nitrogen is lost through volatilization; by quickly incorporating manure into the soil, dung beetles make more of this nitrogen available for plant use.
• The larvae use only 40-50% of the brood ball before pupating, leaving behind the remainder of this nutrient-rich organic matter for soil microbes, fungi, and bacteria to use in creating humus.

More information about scarabs or dung beetles.

Survival of dung beetles is vital to successful agriculture.

A cross reference of other word family units that are related directly, or indirectly, with: "insects, bugs, worms; invertebrates": aphidi-; api-; ascari-; culci-; Dung Beetle Survival; Eating Worms; entomo-; formic-; Guinea worms; helmintho-; insecto-; Insects: Importance; isopter-; larvi-; lepidopter-; meliss-; mosquito; Mosquito, other Languages; Mosquitoes, Pt. 1; Mosquitoes, Pt. 2; myrmeco-; scarab; scoleco-; sphec-; taeni-; termit-; vermo-.