The African Black Beetle (Heteronychus arator) is a significant pest in Australian lawns and gardens. These beetles are notorious for their destructive larvae, which feed on the roots of grasses and other plants, leading to extensive lawn damage.
Lifecycle in Australia
1. Egg Stage: Female beetles lay eggs in the soil during early to late spring. Each female can lay up to 80 eggs.
2. Larval Stage: Eggs hatch into larvae (also known as grubs) within a few weeks. The larvae go through three instars, feeding on plant roots and organic matter. This stage lasts through summer and into early autumn.
3. Pupal Stage: In mid summer, the larvae pupate in the soil. This stage lasts for a few weeks.
4. Adult Stage: Adult beetles emerge in late summer to early autumn. They remain relatively inactive during the colder months and become active again in spring, starting the cycle anew.
Why They Are a Problem for Lawns
• Root Damage: The larvae feed voraciously on grass roots, which weakens the turf, causing it to become spongy and yellow. Severely damaged lawns can develop bare patches.
• Rapid Spread: African Black Beetles can quickly infest large areas due to their high reproductive rate and mobility.
Control Measures
Effective management involves applying a preventative like Acelepryn to protect your lawn all season long. Also monitoring for beetle activity and applying appropriate insecticides like Fortune Ultra when larvae are active. Maintaining a healthy lawn through proper fertilisation, mowing, and watering can also help reduce the impact of these pests.