TreeIssues

Japanese Beetle

MODERATE

Popillia japonica

Overview

An invasive beetle introduced to New Jersey in 1916. Adults skeletonize leaves of over 300 plant species while larvae (grubs) damage turf grass roots. They are particularly damaging to linden, birch, and fruit trees.

Type
Insect
Severity
MODERATE
Source
iNaturalist

Symptoms

Skeletonized leaves with only veins remaining, metallic green and copper beetles feeding in groups, brown patches in lawn from grub damage, defoliation progressing from top of canopy downward

Affected Species

Geographic Spread

Treatments

Hand-Picking and Trapping

Mechanical RemovalEffectiveness: LOW

Physical removal of adult beetles from plants into soapy water. Commercial traps are available but may attract more beetles to the area than they catch.

Grub Control with Milky Spore

Biological ControlEffectiveness: MODERATE

Application of Paenibacillus popilliae (milky spore disease) to turf to kill overwintering grub larvae. Takes 2-3 years to establish but provides long-term control for 10+ years.

Neonicotinoid Soil Application

Chemical TreatmentEffectiveness: HIGH

Systemic insecticide (imidacloprid or clothianidin) applied to soil around high-value plants. Provides season-long protection against adult feeding. Avoid use on pollinator-attractive plants during bloom.

Recommended Products & Tools

Helpful supplies for managing Japanese Beetle. Always read and follow label directions, and confirm a diagnosis before treating.

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Frequently Asked Questions

What is Japanese Beetle?

An invasive beetle introduced to New Jersey in 1916. Adults skeletonize leaves of over 300 plant species while larvae (grubs) damage turf grass roots. They are particularly damaging to linden, birch, and fruit trees.

What are the symptoms of Japanese Beetle?

Skeletonized leaves with only veins remaining, metallic green and copper beetles feeding in groups, brown patches in lawn from grub damage, defoliation progressing from top of canopy downward

Where is Japanese Beetle currently found?

Japanese Beetle is currently active in Alabama, Arkansas, Connecticut, District of Columbia, Delaware, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Maryland, Maine, Michigan, Minnesota, Missouri, Mississippi, North Carolina, Nebraska, New Hampshire, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Virginia, Vermont, Wisconsin, West Virginia, Colorado. It has been reported in 35 total states across the United States.

What plants are affected by Japanese Beetle?

Japanese Beetle affects American Linden, Paper Birch, Apple, Black Cherry, Japanese Maple, Sugar Maple, Azalea, Peach. Susceptibility varies by species.

How do I treat Japanese Beetle?

Treatment options for Japanese Beetle include: Hand-Picking and Trapping, Grub Control with Milky Spore, Neonicotinoid Soil Application. Treatment approaches may include chemical, biological, cultural, and mechanical methods depending on the severity and context.

Compare with Similar Ailments

Not sure if it's Japanese Beetle? Compare it side-by-side with similar ailments.

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