The European chafer (Rhizotrogus majalis) is an invasive species of scarab beetle that resembles the June beetle but is slightly smaller and lighter in colour (tan, rather than dark brown). The adult beetles first emerge from the soil in June and July and mate soon after. The females burrow underground to lay their eggs, which hatch into small grubs two weeks later. The grubs start feeding on plant roots near the surface immediately, but the process can be delayed by several weeks if there isn’t enough moisture in the soil. They burrow deep into the ground under drought conditions, moving back to the surface to feed only when rainfall returns to normal. Larvae begin to seriously damage grass and turf in September, when they reach full size, and will continue feeding on roots all the way into November or December, until frost sends them deep underground. This species overwinters easily and can withstand freezing. The following spring, the grubs return to the surface to feed even before the snow melts and will continue to cause damage to roots and new shoots until mid- to late May, when they pupate; new adults will begin to emerge from these pupae in mid- to late June.
What kinds of plants do they attack?
European chafer beetles are mostly a problem for grass and turf as white grubs, when they’re in their larval stage. The adult beetles feed on foliage but don’t cause any notable damage.
What do they look like, and how do I know if my plants are under attack?
Please consult the general information on white grubs.
How to get rid of European Chafer / Grubs
Koppert offers different solutions for biological pest control of European Chafer / Grubs.