By: Ada Ellisman
When most people think about dung beetles, if they think about them at all, they picture small insects rolling balls of manure across the ground. During my time at White Buffalo Land Trust, I’ve delved into a literature review about these little creatures, and have learned that they are far more than just quirky recyclers; they are important players in maintaining healthy soil.
California has very few native dung beetle
species due to the decline of large mammals and the loss of their dung sources. The few species that still persist are typically not found in areas with cattle production. To address this gap, non-native dung beetles were introduced through government programs aimed at accelerating the decomposition of dung and controlling livestock parasites and fly populations. In 1973, the California Department of Agriculture began raising exotic dung beetles at UC Davis, using breeding stock from Australia and the USDA’s Texas dung beetle project. In 1975, 7,000 beetles from two species were released onto rangelands and pastures. By 1977, after introducing approximately 680,000 beetles to California ranches, federal funding for the program was cut. Farmers, however, continued releasing dung beetles by transporting infested manure to areas where the beetles were needed. Today, several species of exotic dung beetles are well-established in California.
Dung beetles are typically categorized into three functional groups based on their nesting behavior: tunnelers, rollers, and dwellers. Tunnelers dig tunnels beneath a dung pile, either filling the tunnels with dung and laying eggs in different sections or creating a chamber at the base of the tunnel filled with dung. They then divide the dung into brood balls, each with an egg, where the larvae will develop. Instead of tunneling, rollers create a ball of dung, which they roll away from the dung pile to a safe location and bury it underground where they lay their eggs. The dung ball serves as both a nest and a food source for the larvae. Unlike tunnelers or rollers, dwellers do not transport dung or bury it. Instead, they live in the dung pile itself, feeding and breeding within it. They lay their eggs directly in the dung, and the larvae feed on the dung as it decomposes, developing within the pile. These three groups of dung beetles each provide unique contributions to the ecosystem.
Both tunneler and roller dung beetles play a vital role in nutrient cycling by burying dung into the soil, which helps reduce surface waste and promotes the breakdown of organic matter. Their actions lower the risk of parasite and pathogen spread, preventing harmful organisms from breeding and multiplying in manure at the soil’s surface. Tunneler dung beetles have the added function of improving soil aeration. By loosening compacted soil, they enhance water infiltration and encourage healthy plant root growth. By feeding on dung on the soil surface, dweller dung beetles help decompose organic matter quickly, aiding in nutrient cycling. They also help control populations of dung-breeding flies by competing for the same habitat, reducing the potential for fly infestations that can cause issues for cattle.
In addition to their direct benefits to soil health and fly control, dung beetles play an essential role in sustainable agricultural practices, such as regenerative grazing. Their natural manure recycling process supports healthy, nutrient-rich soil while reducing the need for chemical fertilizers and pesticides. By incorporating dung beetles into grazing systems, farmers can help restore soil biodiversity, improve pasture quality, and create a more resilient and regenerative farming environment. Dung beetles are, indeed, nature’s tiny engineers, contributing to the long-term health and productivity of the land.
I’m particularly excited to witness these little guys spring into action on our ranch once our cattle arrive!
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