Insect Management Handbook

Ceutorhynchus assimilis

Pest description and crop damage Small, dark gray snout beetles that congregate on blooms. Larvae feed on seeds inside pods.

Management-chemical control

Delia radicum

Pest description and crop damage White maggots that feed on roots and underground stems and weaken, lodge, and kill plants. Evidence of larval damage will present as withering leaves developing a bluish hue and delayed plant growth. Larvae do not tolerate extended period of high temperature. Adult is a small gray fly that lays white eggs at plant bases.

Management-chemical control

See:

Trichoplusia ni

Pest description and crop damage Pale green larvae with white stripes on back and sides. They move in a looping manner.

Management-chemical control

See:

Radish-Looper

Includes:

Cabbage aphid (Brevicoryne brassicae)
Green peach aphid (Myzus persicae)
Turnip aphid (Lipaphis pseudobrassicae)

Limonius spp.

Pest description and crop damage Wireworms are the soil-dwelling larvae of click beetles. Adult click beetles are slender, and tan to nearly black. Larvae are hard, segmented, and dark yellow or brown. Wireworms injure seedlings by feeding on roots or boring into stems. Damage is more common in spring planted crops where the soil has a high organic content, such as fields that recently have been in or adjacent to alfalfa, pasture, or uncontrolled weeds.

Includes

Gray field slug (Deroceras reticulatum)
Greenhouse slug (Milax gagates)
Marsh slug (Deroceras laeve)
Red slug (Arion spp.)
Reticulated slug (Prophysaon andersoni)
Spotted garden slug (Limax maximus)

Includes

Armyworns

Armyworm (Pseudaletia unipuncta)
Beet armyworm (Spodoptera exigua)

Loopers

Alfalfa looper (Autographa californica)
Cabbage looper (Trichoplusia ni)

Includes

Green peach aphid (Myzus persicae)
Lettuce aphid (Nasonovia ribis-nigri)

Ctenicera spp. and Limonius spp.

Pest description and crop damage Slender shiny brown to yellow grubs with hard bodies. Wireworms are the larvae of click beetles. Wireworms live in the soil where they may feed on corn seeds or the roots of young plants. Damage typically occurs during the early stages of crop development.

See also:

Striacosta albicosta

Pest description and crop damage Large brown caterpillars that feed on foliage and burrow into ears. Female moths lay egg masses on corn foliage. The caterpillars will move from plant to plant, and individuals from a single egg mass may infest nearby plants within a 6 to 10-foot circle.

Management-chemical control

Treat when egg masses or larvae are present.