Chafer grubs are common across the UK and Europe, and are often found in the upper soil levels beneath turf. They are easily recognised by their large, curved white bodies, light brown heads, and several pairs of legs near the head. While the adult beetles themselves do not damage turf, their larvae feed on grass roots, which can lead to significant damage if they are present in large numbers.

Identifying Chafer Grub Damage

In low numbers they may not cause much harm, but a large infestation can result in patches of yellowing and dying grass. These grubs attract wildlife such as birds, hedgehogs, foxes, and badgers, which can further damage your lawn whilst hunting for these nutritious pests. Consequently, large areas of your lawn can be devastated if the problem is not addressed.

Considering the Ecosystem

Before taking action against chafer grubs, it’s important to consider their role in the ecosystem. They serve as a food source for various wildlife, so eliminating them will also affect the local wildlife that depends on them for sustenance.

Biological Control: Using Nematodes

One effective and natural method to control chafer grubs is the use of nematodes. These microscopic organisms, which move like eels or worms, are natural parasites of chafer grubs. Nematodes invade the grubs through natural body openings and release bacteria that kill the grubs by stopping them from feeding. The nematodes then reproduce inside the dead grubs, releasing a new generation of infective juveniles that disperse into the soil to find more prey.

Ready-made nematode products can be easily mixed with water and applied to your garden. This natural solution is safe, effective, and can reduce chafer grub populations in just a few days.

Chemical Control: Professional Treatment

Chemical treatments for chafer grubs are not available for consumer use in the UK and must be applied by licensed professionals. These experts are trained in the safe use and application of pesticides, which are effective against chafer grubs and leatherjackets in managed turf areas. Due to legal requirements, only certified professionals with adequate training can use such products.

Optimal Timing for Grub Control

Chafer grubs are most active between May and August, making this the best time to apply grub control measures. It is crucial to target them early while they are still small, as larger grubs are harder to eliminate. Always follow the product label instructions, but generally, the soil should be at least 10°C for effective treatment.

Leatherjackets: Another Garden Pest

Leatherjackets, the larvae of the European Crane Fly (Daddy Long Legs), can cause similar damage to that of chafer grubs. These legless, grey larvae feed on grass roots and can be identified by the presence of numerous Daddy Long Legs in your garden. Nematodes can also control leatherjackets in the same way they manage chafer grubs. Chemical treatments, similar to those used for chafer grubs, should only be applied by qualified professionals.