Blueberries: Japanese Beetles (White Grubs)

Japanese Beetle (Popillia japonica) adults feed on blueberry leaves:

Japanese beetle on leaf. Beetle has shiny bronze wings with white stripy area between wings and abdomen. Thorax and head are dark shiny green. Short antenna end in small black structure resembling palm frond. — Adult Japanese beetle.

Blueberry plant with orange, dead leaves covered in small lacy holes. — Feeding damage on leaves.

Feeding damage on leaves:

Close-up blueberry leaf. Half of leaf is healthy and green. Half of leaf has orange dead tissue riddled with little round holes. — Feeding damage on leaves.

Adults may also feed on the skin of berries.

Blueberry cluster. Blueberry skin is shriveled and riddled with little holes. One Japanese beetle perches on a blueberry. Two beetles below cluster are mating on leaf riddled with holes. — Japanese beetle damage to blueberry fruit.

Larvae (grubs) of Japanese Beetles live in the soil for much of the year and will feed on newly planted strawberry, blueberry and raspberry roots, especially plantings following sod or on lighter soils.

Close-up of single grub. Grub is C-shaped and has a dark brown head and three orange legs. The body is fat and cream-colored, appears shiny. — Japanese beetle (*Popillia japonica*) grub

Larvae feeding on roots cause much more damage than adult beetles.

Beetle on leaf. Beetle has shiny bronze shell and green head with black and white stripes on underbelly. — Japanese Beetle adult (Popillia japonica)

More information on Japanese Beetles (White Grubs):

Midwest Small Fruit Pest Management Handbook – (pages 46-47)
White Grubs (OMAFRA)
Japanese Beetles (University of Minnesota)

Use these resources if you need additional help with diagnosis and to find solutions to your problem.