The redhumped caterpillar is the larvae of a 1" gray-brown moth. The mature larvae are yellow with a red head and hump, and have orange, black, and white lengthwise stripes. The body of the caterpillar also has dark "spikes" on it. Young redhumped caterpillars are found in clustered colonies which disperse as caterpillars mature. They eat entire leaves (except the major veins) and can cause considerable defoliation.

Management Options

Non-Chemical Management

Cut out and destroy colonies before they disperse.
Hand-pick and destroy individual caterpillars.

Select non-chemical management options as your first choice!

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides

Apply when caterpillars are first noticed. Use a spreader-sticker with liquid Bt formulations. Homeowners should not make foliar applications to trees over 10 ft tall. Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.

Bonide Captain Jack's Deadbug Brew R-T-U [Organic]
Active ingredient: spinosad (spinosyn A+D) | EPA reg no: 4-472
Safer Brand BioNEEM Multi-Purpose Insecticide & Repellent Conc [Organic]
Active ingredient: azadirachtin | EPA reg no: 70051-6-42697
Safer Brand Caterpillar Killer for Trees, Shrubs & Vegetables Conc II [Organic]
Active ingredient: Bacillus thuringiensis subsp. kurstaki | EPA reg no: 70051-106-42697
Safer Brand Caterpillar Killer/Trees, Shrubs, & Vegetables Conc
Active ingredient: Bacillus thuringiensis subsp. kurstaki | EPA reg no: 42697-23
This list may not include all products registered for this use.

Images

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Caption: Redhumped caterpillars Photo by: A.L. Antonelli
Caption: Redhumped caterpillar adult Photo by: A.L. Antonelli

WSU Extension

Hortsense