Dung beetles are among the most ecologically important insects on the planet, yet they rarely receive the recognition they deserve. These industrious members of the superfamily Scarabaeoidea perform a suite of vital ecosystem services that benefit soil health, plant growth, parasite control, and even greenhouse gas reduction. Without dung beetles, the world's grasslands and pastures would be buried under mountains of unprocessed animal waste.
Types of Dung Beetles
Dung beetles are broadly classified into three functional groups based on how they process dung:
| Type | Behaviour | Examples |
|---|---|---|
| Rollers (telecoprids) | Shape dung into balls and roll them away from the dung pat to bury elsewhere | Sacred scarab (Scarabaeus sacer), Kheper species |
| Tunnellers (paracoprids) | Dig tunnels directly beneath the dung pat and pack dung into underground chambers | Onthophagus species, Copris species |
| Dwellers (endocoprids) | Live and breed inside the dung pat itself, feeding and laying eggs without moving the dung | Aphodius species (common in the UK) |
Dung Beetles in the UK
- Approximately 60 species of dung beetle are found in the UK
- Most belong to the genus Aphodius (dwellers) and Onthophagus (tunnellers)
- The UK has no native roller species — rollers are predominantly tropical
- The minotaur beetle (Typhaeus typhoeus) is one of the UK's most impressive tunnellers, digging burrows up to 1.5 metres deep
Ecosystem Services Provided by Dung Beetles
Nutrient Recycling
Dung beetles are the primary agents of dung decomposition in most terrestrial ecosystems. By burying dung beneath the soil surface, they return essential nutrients — nitrogen, phosphorus, and potassium — to the root zone where plants can absorb them. A single dung pat left on the surface may take months or even years to decompose naturally; dung beetles can process it within days.
Soil Improvement
The tunnelling activity of dung beetles aerates the soil, improves water infiltration, and redistributes organic matter to deeper soil layers. Research has shown that dung beetle activity can increase water infiltration rates by up to 129% in compacted pastures. The buried dung also feeds soil microorganisms, enhancing soil biological activity and fertility.
Parasite Control
Livestock dung is a breeding ground for parasitic flies and intestinal parasites. By rapidly burying or processing dung, beetles disrupt the life cycles of these parasites. Studies have demonstrated that dung beetle activity can reduce the emergence of pest flies from cattle dung by up to 95% and significantly reduce the viability of parasitic worm eggs and larvae.
Seed Dispersal
When dung beetles bury dung that contains seeds from the fruits eaten by herbivores, they inadvertently plant those seeds at an ideal depth for germination. This process, known as secondary seed dispersal, is particularly important in tropical forests where many plant species depend on large herbivores and dung beetles for seed distribution.
Greenhouse Gas Reduction
Decomposing dung on the soil surface produces significant quantities of methane, a potent greenhouse gas. By burying dung and promoting aerobic decomposition underground, dung beetles can reduce methane emissions from livestock dung by up to 40%, according to recent research. Globally, this represents a meaningful contribution to reducing agricultural greenhouse gas emissions.
Did you know? When dung beetles were introduced to Australia in the 1960s and 1970s to deal with the country's cattle dung problem, the results were dramatic. Australia had no native dung beetles adapted to cattle dung (native beetles evolved with marsupial dung), and unprocessed cattle pats were smothering millions of hectares of pasture. The introduction of African dung beetle species transformed Australian pasture management.
Threats to Dung Beetles
Despite their ecological importance, dung beetles face several threats:
- Veterinary pharmaceuticals: Ivermectin and other antiparasitic drugs used to treat livestock pass through into the dung and are highly toxic to dung beetles and their larvae. This is considered the single greatest threat to dung beetle populations worldwide.
- Habitat loss: The conversion of pastures to arable land eliminates dung beetle habitat
- Intensive farming: Indoor livestock housing removes dung from the field ecosystem entirely
- Climate change: Altered temperature and rainfall patterns affect beetle activity and survival
The Economic Value of Dung Beetles
The ecosystem services provided by dung beetles have been valued at billions of pounds annually worldwide. In the United States alone, dung beetles are estimated to save the cattle industry approximately $380 million per year through dung removal, soil improvement, and parasite control. In the UK, their services to pasture management and soil health are similarly significant, though less frequently quantified.
Key Takeaway
Dung beetles are ecological powerhouses that provide essential services including nutrient recycling, soil improvement, parasite control, seed dispersal, and greenhouse gas reduction. Their work underpins the health of grassland ecosystems and saves agriculture billions of pounds annually. The widespread use of ivermectin-type drugs in livestock poses a serious threat to these vital insects, and more sustainable parasite management approaches are urgently needed.