Masked Chafers & Japanese Beetle Turfgrass Pest
Type of damage:
Masked chafer grubs feed on roots, resulting in irregular dead patches. Symptoms resemble drought stress and persist even where there is sufficient irrigation. Grub activity can cause the ground to feel spongy; extensive root feeding sometimes allows the turf to be rolled back like a carpet. Most damage usually takes place in late summer or early fall. Digging by vertebrate predators, such as crows, raccoons, skunks, and coyotes, is a common indication of high grub populations.
Large C-shaped beetle larvae that feed on roots of turfgrass plants. These grubs are white, up to 1 inch in length, with dark translucent dorsal stripes, brown head capsules, and legs.
Adult Masked Chafer Grub Description:
Adult beetles are golden brown, hairy on the underside of the thorax, and have a darker brown head.
Adult beetles emerge in late June–early July
- Burrow into soil to lay egg
Larvae hatch by early August
- Feed and damage roots into fall
- Burrow deeper for the winter
- Burrow up to the root zone in spring to feed
Pupate in late Spring
- When soil reaches 50 degrees
How are these grubs controlled
Thorough spike-aeration of turf kills significant portions of white grub populations when they are feeding close to the soil surface.