Dung beetle

Systematic position: The dung beetle (Geotrupes spiniger) belongs to the order Coleoptera and the family Scarabaeidae. Although they are ecologically beneficial as decomposers, they can act as pests in specific agricultural settings due to their extensive burrowing behavior that disrupts soil structure.

Crops affected: The primary concern involves pastures, golf courses, and lawns. While these beetles are primarily coprophagous, their burrowing activity can cause indirect damage to the roots of grasses and young crops. In areas with high beetle density, the integrity of the soil surface is compromised, leading to economic loss in forage production.

Biology and life cycle: The lifecycle of Geotrupes spiniger consists of egg, larval, pupal, and adult stages. Females excavate deep subterranean tunnels, packing them with dung to serve as food for their larvae. The larvae develop within these chambers, undergoing several instars before pupating in the soil. Development typically lasts from one to two years, depending on the ambient temperature and soil moisture levels.

Damage and pest status: Damage is largely mechanical. The construction of tunnels results in the uplifting of soil and the disturbance of the root zone, leading to weakened plant growth and increased susceptibility to drought. On intensively managed pastures, these disturbances can lead to significant surface damage and reduced yield of palatable forage grasses.

• Regular harrowing of pastures to break up dung piles.
• Managing livestock density to limit available breeding sites.
• Maintaining healthy turf to improve soil resistance.
• Monitoring populations during peak adult activity periods.

Management practices: Controlling Geotrupes spiniger focuses on cultural and management strategies rather than chemical pesticides. Breaking up dung pats immediately after deposition prevents beetles from finding suitable sites to establish brood chambers. Promoting a healthy soil ecosystem and ensuring adequate moisture in pastures also helps mitigate the impact of tunnel digging on plant health.