Chafer Grubs (the larvae of the Chafer Beetle) are a menace and can do severe damage to your lawn. If you are unfortunate and have your lawn infested with chafer grubs, it’s now a real challenge to control them since EU regulations have banned previously available professional-only solutions. Whilst that can be seen as a good thing for the environment, it does mean chafer grubs are free and able to cause significant damage to a lawn, be it directly from eating the grass roots or secondary damage from wildlife ripping up the surface to get at the grubs.
With prevention being better than cure, you could try Chafer traps or lures. The traps contain a pheromone to imitate a female chafer beetle, luring male chafer beetles on the premise of mating. Once caught in the trap, they are unable to get out and procreate. This helps reduce the chafer eggs laid in a lawn and, in turn, the number of grubs able to inflict that associated secondary damage. not Whilst they should not be seen as a cure, Traps should certainly be seen as a mitigating approach. The damage wreaked by these hungry little monsters should be underestimated, often necessitating a complete replacement lawn, so anything we can do to interrupt their breeding cycle has to be a positive thing.
An inexpensive, reusable trap like the ones pictured here will cost around £20 (as of Feb 2019) from a countryside store or your local independent lawn care specialist. This setup will typically cover an area up to 2000m2, with a replaceable pheromone pack lasting up to 6 weeks. Wearing gloves, open the pheromone pack and place it inside the trap. This needs to be suspended 50-100cm high off the ground in a lawned area. Ensure that’s done in May and June when the adult chafer beetles will be most active and seeking to mate. Be mindful of keeping children away from the trap and the pheromone lure. If you have chafer beetle activity you should see adult beetles in the trap within a few days. It’s advisable to repeat the use of the traps annually.
Chafer beetle trap installed in a garden:

