Imported Cabbage Worm - Pieris rapae (Linnaeus)

Dr. Phillip Roberts, Extension Entomologist, The University of Georgia, Department of Entomology, Tifton, GA 31793
Dr. Paul Guillebeau, Extension Entomologist, The University of Georgia, Department of Entomology, Athens, GA 30602

Order Lepidoptera: Family Pieridae

Description: Adult: wingspan about 2 inches (male slightly smaller), with a black area near the tip of the forewing and a small black spot on the front edge of each hind wing. Female has two black spots on each forewing; male has only one. Larvae: velvet-like green, with a faint yellow stripe down its back, a row of faint yellow spots on each side, and five pairs of prolegs. Up to 1.4 inches long. Host Plants: Prefers cabbage, broccoli, and cauliflower but also feeds on turnip, kale, collards, radish, mustard, horseradish, and lettuce. Damage: Larvae commonly found on the undersides of leaves. Young caterpillars feed superficially, leaving the upper leaf surface intact. Larger larvae leave holes in the leaves. Commonly bore into the center of the cabbage head. Typically leaves masses of wet, greenish brown excrement deep among leaves.

Imported Cabbage worm butterflies Photo by: David Adams, UGA

Imported Cabbage worm butterfly Photo by: David Adams, UGA

Life Cycle: Overwinter as pupae attached to host plant debris. Adults emerge as early as March and lay eggs singly on cultivated host plants, if available. First generation often on wild hosts. Larvae hatch in 4-8 days and feed for 10-14 days. Mature larvae fasten themselves to lower leaf surfaces by silk bands. Moths emerge in 7-12 days. Life cycle lasts from 3-5 weeks. Three to four generations per year

Control: A number of disease organisms and parasites attack larvae, but cultural and/or chemical control practices may be necessary. Resistant varieties can be helpful. New plantings should not be planted near previous years' fields. Do not delay harvest;destroy plant residues. Organophosphates, carbamates, pyrethroids, or Bacillus thuringiensis may be recommended.

In: Roberts, P. M. and G. K. Douce, Coordinators. 1999. Foliage Feeding Insects. A County Agent's Guide to Insects Important to Agriculture in Georgia. Univ. of GA, Col. Ag. Env. Sci., Coop. Ext. Serv., Tifton, GA USA. Winter School Top Fifty Agricultural Insect Pests and Their Damage Sessions, Rock Eagle 4-H Ctr., Jan. 20, 1999.

Selected References and Suggested Readings