Japanese beetles

Japanese beetles
Rufus Isaacs, MSU Entomology

Japanese beetles can be present from June through September. They feed on the upper leaf surfaces, leaving a lacelike skeleton. Injured leaves may turn brown and die if feeding is severe, but clusters are not attacked. Juice grape vines are resistant and tolerate some damage, but vinifera and hybrids are more susceptible.

This pest can be a problem particularly in new vineyards using grow tubes. Frequent monitoring is required to reduce the risk of severe damage. Japanese beetle traps may attract beetles to vineyards, so their use is discouraged.

Beetles lay eggs underground in grassy areas near vineyards, preferring soil with moisture. The white, C-shaped larvae (grubs) feed on grass and weed roots and overwinter underground in these areas. Cultural and biological controls of grubs may reduce subsequent abundance of adults.


Japanese beetles are about 12mm long. Photo: Rufus Isaacs

Additional information

Search MSU Fruit CAT Alert newsletter for articles. Type in keyword: Japanese beetles
Vineyard Scouting Calendar for Key Pests
View fact sheet developed by Mark Longstroth, MSUE Van Buren County.
Recommendations from the Michigan Fruit Management Guide

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Funding for this web site provided by Project GREEEN, American Farmland Trust, EPA Region 5's Strategic Agricultural Initiative program, The National Foundation for IPM Education, the Center for Agricultural Partnerships and the MSU Integrated Pest Management Program
in collaboration with MSU Extension and the Michigan Agricultural Experiment Station.
Updated 11/05/07 Contact: J.N. Landis.