Cole Crops

Pests and their Damage: Planting to Rosette

ON THIS PAGE:
  • Aphids, other
  • Bagrada bug
  • Beet armyworm
    (eggs and newly hatched larvae)
  • Cabbage aphid
  • Cabbage looper (eggs and newly hatched larvae)
  • Cabbage maggot
  • Crickets
  • Darkling beetle
  • Diamondback moth (coastal areas)
  • Flea beetle
  • Garden symphylan
  • Grasshoppers
  • Leafminer
  • Seedcorn maggot
  • Silverleaf whitefly
  • Sowbugs
  • Wireworm
Click on photos to enlarge. Names link to more information on identification and management.
Green peach aphids.

Aphids, other

Identification tips: Green peach aphids are dark green or yellow and have no waxy covering. They are the most common in cole crops, but also look for turnip aphid.

Adult female Bagrada bug, Bagrada hilaris, (left) and adult male (right).

Bagrada bug

Identification tips: Adults are about 0.2 inch and have black, shield-shaped bodies with distinct orange and white markings. Look for stippled or wilted areas on leaves and new shoots or heads of plants that become stunted.

Beet armyworm egg cluster.

Beet armyworm

Identification tips: Adults lay their eggs in scale-covered cottony masses on leaf surfaces. Larvae are dull green and have light-colored stripes down the back and sides. They can destroy seedlings, consume leaves, or stunt growth by feeding on buds.

Cabbage aphid wingless adult.

Cabbage aphid

Identification tips: Grayish-green with a white waxy coating. Dense colonies covered with waxy droplets develop. They are found feeding deep within the heads of cabbages or Brussels sprouts.

Cabbage looper egg.

Cabbage looper

Identification tips: Cabbage looper eggs are ridged and dome-shaped and usually laid individually on the underside of leaves. Larvae are 1 to 1.5 inches long, green, and crawl by arching their bodies. Loopers chew ragged holes in leaves and bore through and contaminate heads and leaves.
Cabbage maggot larvae and brown pupal case.

Cabbage maggot

Identification tips: Larvae are small, legless, white maggots usually less than 0.33 inch long. Adults are small, dark gray flies. They feed on roots and young plants are most susceptible.

Field cricket nymph.

Cricket

Identification tip: Adult crickets are black or brown, and are about 0.5 to 1 inch in length. They can damage seedlings.

Darkling beetle adult.

Darkling beetle

Identification tips: Adults are dull bluish black or brown beetles that chew off seedlings or feed on foliage. Be careful to distinguish from predaceous ground beetles, which are shinier and have enlarged segments at the tip of the antennae.

Diamondback moth larva.

Diamondback moth

Identification tips: Larvae are greenish, about 0.33 inch long, and wider in the middle. They feed on leaves, buds, and stalks. Damage is most serious on the growing points of young plants.

Potato flea beetle adult.

Flea beetle

Identification tips: Small brown or black beetles that jump like a flea when disturbed. Check underside of leaves and look for small pits or irregularly shaped holes in leaves.

Garden symphylan.

Garden symphylan

Identification tips: Less than 0.33 inch long with 15 body segments, and 11 to 12 pairs of legs. Slender, elongated, and white with prominent antennae.

Adult devastating grasshopper.

Grasshoppers

Identification tip: The adults are elongate, robust, winged and good flyers. Commonly brown, gray, green, or yellowish with greatly enlarged hind legs adapted for jumping. The somewhat similar cricket has longer antennae and is darker.
Adult vegetable leafminer.

Leafminer

Identification tips: Adults are tiny black flies with a bright yellow spot on their thorax; larva mine between the upper and lower leaf surfaces, creating winding white tunnels that widen as the larva grows.

Larva (top), prepupa (left), and pupae (center) of seedcorn maggot, Delia platura.

Seedcorn maggot

Identification tips: Mature larvae are small whitish maggots. Pupae are small brown capsules. Adult is light gray fly. Look for clusters of eggs near plant stems. Be sure to distinguish from the cabbage maggot.

Silverleaf whitefly adult.

Silverleaf Whitefly

Identification tips: Adults are about 0.5 inch long, yellowish insects with white wings. Feeding causes leaves to turn whitish or silver.

Adult sowbug.

Sowbugs

Identification tips: Adults have seven pairs of legs and are dark gray or brown but may be almost purple or blue just after molting. They feed on seedlings.

Sugarbeet wireworm larvae.

Wireworm

Identification tips: Slender, elongate, yellowish to brown with smooth, tough skin resembling mealworms. Look in soil for damage to roots and holes bored through stems. Seedlings are most susceptible.

 

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