The Dune chafer (Anomala dubia) is a soil-dwelling beetle pest whose larvae (white grubs) cause serious damage to roots in turfgrass, nursery crops and young trees. Instead of chemical pesticides, biological control provides a sustainable, effective way to manage infestations. Beneficial organisms such as beneficial nematodes target larvae directly in the soil, protecting plants and maintaining ecological balance.
Adults: Medium-sized beetles (12–16 mm long) with a shiny brown to reddish-brown body. They resemble other scarab beetles but are slightly slimmer. Adults fly at dusk in late spring and early summer and are attracted to lights. They often swarm over grasses and crops to mate and lay eggs.
Larvae (grubs): C-shaped, creamy white with a brown head capsule and three pairs of legs. Fully grown larvae reach up to 25 mm in length. They live in the soil and feed on roots of grasses, ornamentals, and young trees.
The larval stage is the most destructive, making it the main target for biological control.
Infested plants show poor growth, yellowing leaves, and wilting despite adequate water. In turf, patches of dead grass may appear, which can be easily lifted due to destroyed root systems. Secondary damage often occurs when birds, wild boar, or other animals dig up the soil to feed on the grubs.
The most effective and sustainable way to control Dune chafer larvae is by applying beneficial nematodes. These naturally occurring soil organisms are highly specialized predators of beetle larvae. Once applied, they actively seek out the larvae, penetrate them, and release symbiotic bacteria that quickly kill the host. After reproducing inside the larvae, new nematodes are released into the soil to continue the cycle, providing ongoing protection.
The beneficial nematode Heterorhabditis bacteriophora (Capyphor) is proven highly effective against Dune chafer grubs (Anomala dubia), actively searching for larvae in the root zone. Apply nematodes when Dune chafer larvae are young and actively feeding (late summer to early autumn, or spring before pupation). Ensure the soil is moist before, during, and after application to help nematodes move through soil pores and find larvae.
