How to Manage Pests

Pests in Gardens and Landscapes

Diamondback moth—Plutella xylostella

Mature diamondback moths are small, green yellow caterpillars with black hairs and are only 0.33 inch long. The body is slender and pointed at both ends, with a distinctive V formed by two prolegs at the rear end.

Life cycle


Larvae may cause small holes in leaves, which is usually not serious, except when the wrapper or cap leaves of cabbage are injured. Growing points or crowns of young plants may be chewed, causing stunted growth. Some larvae may bore into heads of broccoli or cauliflower, causing contamination.


Natural enemies often effectively control diamondback moth in California. Applications of Bacillus thuringiensis or spinosad are also very effective. Older plants are not usually seriously damaged. Destroy culls and mustard-type weeds several weeks before planting.

Diamondback moth adult
Diamondback moth adult

Holes in leaves caused by larvae
Holes in leaves caused by larva

Statewide IPM Program, Agriculture and Natural Resources, University of California
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