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Home > Bugs > Bugs of Vegetables > Cabbage Worms

Cabbage Worms

Cabbage LooperTrichoplusia ni

Diamond Back MothPlutella xylostella

Imported CabbagewormPieris rapae

 

Three caterpillars can be voracious pests of cabbage, broccoli and other cole crops*. If allowed to become numerous they can completely defoliate plants. Minor infestations make plants look unsightly and can cause reduced yields and increased decay.

In addition to cole crops, the cabbage looper may also feed on lettuce, soybeans, tomatoes and some annual flowers.

(*Brassica is a genus of plants in the Brassicaceae family. Crops from this family are sometimes called cole crops, which comes from the Latin for stem or cabbage. Vegetables of this family are called cruciferous vegetables or crucifers because the four petals of their flowers resemble a cross. Brassicas, cole crops, and crucifers are all terms refering to cabbage, broccoli, cauliflower, Brussels sprout, turnip, kale, radish, rutabaga, collards and the like.)

 

Cabbage Looper—Trichoplusia ni

cabbage looper larvae cabbage looper adult cabbage looper damage
The cabbage looper larvae grow to about 2 inches, and are light green with a few white or pale yellow stripes. They move with a characteristic "looping" motion similar to inchworms. Adult moths are mottled grayish brown with a 1 1/2 inch wing span. Each forewing is marked near its center with a pair of silver markings. Larvae eat large irregular holes in the outer leaves of cabbage plants, sometimes eating into the head of cabbages. Heavy infestations result in skeletonized plants as all but the leaf veins are usually eaten.
     

Diamondback Moth—Plutella xylostella

diamondback moth larvae diamondback moth adult diamondback moth larval damage
Diamondback moth larvae are 1/4 to 1/3 inch long, tapered at both ends, pale yellowish-green, with fine, scattered black hairs over the body and a black head. They wriggle rapidly when disturbed, often dropping from the plant and hanging by a silk-like thread. The adult is a grayish-brown moth with narrow front wings, fringed hind wings and a wing span of about 3/4 inch. When at rest the wings come together to form a line of white or pale yellow diamonds down the middle of the back. Larvae feed on all plant parts; they eat small holes in leaves and buds, but prefer the undersides of older leaves, leaving "shothole" type damage.
     

Imported Cabbageworm—Pieris rapae

imported cabbageworm larvae imported cabbageworm adult imported cabbageworm damage
The imported cabbageworm larvae is velvety green, about 1 inch long, and tends to be sluggish. They feed and rest on the underside of leaves. The adult of the cabbageworm is an off-white butterfly with one or two grayish-black spots per wing and a wing span of about 2 inches. Larvae feed on foliage and can reduce mature plants to stems and veins. They prefer leafy foliage, but will burrow into the heads of broccoli and cabbage. Fecal pellets can be found between the leaves.

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Identification and Control Information (each will open in a new window)

 

 

 

[Photos, left to right: Alton N. Sparks, Jr., University of Georgia, Bugwood.org; Keith Naylor, Bugwood.org; David Riley, University of Georgia, Bugwood.org; Russ Ottens, University of Georgia, Bugwood.org; Russ Ottens, University of Georgia, Bugwood.org; Alton N. Sparks, Jr., University of Georgia, Bugwood.org; Russ Ottens, University of Georgia, Bugwood.org; Whitney Cranshaw, Colorado State University, Bugwood.org; Whitney Cranshaw, Colorado State University, Bugwood.org]

 
It is the policy of the State of Maine to minimize reliance on pesticides. The Maine Department of Agriculture and the Maine IPM Council encourage everyone to practice integrated pest management and to use pesticides only as a last resort. The mention of pesticides in the fact sheets linked to these pages does not imply an endorsement of any product. Be sure that any product used is currently registered and follow all label directions.