Life Cycle
The life cycle of the grass grub is comprised of several stages:
- Egg Stage: The female grass grub beetle lays 50 eggs in batches of 10-40, typically 75-175mm below the soil surface. The eggs are light in colour and oval-shaped. In ideal conditions, they hatch into larvae in about three weeks.
- Larvae Stages (Grub Stage):
- First Larval Stage: After hatching, the grubs begin feeding, lasting about 4-5 weeks.
- Second Larval Stage: The grubs continue feeding and growing larger, lasting 5-10 weeks. During this stage, the grubs are in the top 25mm of the soil, which makes them easier to treat.
- Pupal Stage: After feeding, the grubs move deeper into the soil (below 25mm) to pupate. This stage lasts around 4-6 weeks before the adult beetle emerges.
- Adult Stage: The adult beetles emerge from the soil between late October and January. They feed on trees, shrubs, roses, and grasses. Their primary damage occurs during their larval stage when they feed on plant roots.
Control Methods
Several treatments are available to effectively combating grass grub in lawns. Many of these products require water for activation, and repeat applications may be necessary for long-term control. Come in and see us to see what product will best suit your needs—it all depends on the time of year and the grass grub's stage of life cycle.
Application Tips
Water Activation: Apply the products when sufficient moisture is present or ensure proper watering after application.
Reapply: Multiple applications may be necessary, especially if the pest pressure is high or previous treatments are not fully effective.
Timing: The best time to apply control treatments is during the grub's larval stages when they are close to the soil surface, typically between late autumn and early winter.
Understanding the grass grub's lifecycle and using the appropriate control methods can protect your garden or pasture from the significant damage these pest’s cause. The key is persistence, correct application, and choosing the right treatment for your needs.
