Pests in the Urban Landscape
Article

Check for Cabbageworms!

A white butterfly with a black spot on its wing feeding on a purple flower.
Cabbageworm butterfly. Photo by Jack Kelly Clark.

If you recently planted cabbage, broccoli, or kale, (often called Brassicas and cole crops) keep an eye out for cabbageworms!

The adult cabbageworm is a white butterfly with one to four black spots on its wings. They lay eggs individually on the leaves of brassica plants. Larvae are green caterpillars that chew on the leaves and may also damage cabbage heads.

Prevent cabbageworm butterflies from laying eggs on your vegetables by covering plants with a floating row cover or insect netting. Check leaves for tiny cabbageworm eggs and squish them. Cabbageworm caterpillars can also be handpicked or squished. Pesticides such as Bacillus thuringiensis or spinosad are very effective if the number of caterpillars is too difficult to manage by hand. Natural enemies, such as tachinid flies, can help control cabbageworms.

Several light green caterpillars feeding on a dark green leaf with a purple stem.
Cabbageworm larvae on a leaf. Photo by Ansel Oommen, Bugwood.org.

To learn more about cabbageworms, visit https://ipm.ucanr.edu/PMG/GARDEN/VEGES/PESTS/importcabwrm.html

Small white egg laid in the middle of a green leaf.
Single cabbageworm egg. Photo by Whitney Cranshaw, Colorado State University, Bugwood.org.