Nematodes to control lawn chafer

Credit: iStock

Q: Help! What can I apply to my lawn to eliminate the European chafer beetle larvae?

The most effective biological control is a nematode (or roundworm), Heterorhabditis bacteriophora – a natively occurring species that has been used successfully in B.C. to control other pests, such as the black vine weevil. This nematode is a carnivorous hunter that actively seeks out the grubs.

The nematodes are available at garden centres in late June to early July and are easy to use. It is as simple as watering the area with the biological treatment. One treatment will cover roughly 100 square m (1100 sq. ft.).

It may not completely eradicate the pest, but if accompanied by good lawn practices it will reduce the infestation. Another good practice is to let the skunks and raccoons eat as many as they can, then overseed with a fast-growing grass seed, such as a shady lawn blend, and get things going with a controlled-release fertilizer.