Common Names: Flea Beetle, Leaf Beetle
Scientific Name: Order Coleoptera, family Chrysomelidae, several species
Size: Adult--1/10" to 1/16"
Identification: Shiny black, blue-black, or brown-black beetles about the size of a pinhead. Some have stripes or other faint markings. They jump like fleas when approached, due to enlarged hind legs. Adults are black, brown, or bronze. Some of the brown species are much larger. Larvae are legless grubs with brown heads. Have chewing mouthparts. Larvae look like thin white worms.
Biology and Life Cycle: Adults overwinter in the soil and emerge in the spring. They feed, lay eggs on plant roots, and die by mid-summer. Larvae hatch and feed for two or three weeks, then pupate in the soil. Adults emerge in two or three weeks. There are one to four generations a year. Complete metamorphosis.
Habitat: Most vegetables, some flowers, and weeds. Soil and plant foliage.
Feeding habits: They eat small round holes in the leaves of potatoes, peppers, beets, brassica, and other crops. Young sprouts are often a target. Leaves are skeletonized, giving plants a bleached appearance before they wilt and die. Larvae feed on roots and tubers below ground. They leave brown snake-looking marks on potatoes.
Economic Importance: Adult beetles chew holes in leaves, especially in the early spring. Larvae damage plant roots.
Natural control: Beneficial nematodes control the larvae in the soil. Encourage biodiversity in the garden: plant a varied mix of crops along with susceptible plants. Encourage biodiversity of insects, birds, plants, and small animals and spray Garrett Juice plus citrus oil. Neem sprays will also help. Fleas can be controlled with good nutrition. Animals with decent diets will not have serious flea problems. See Malcolm Beck's book Lessons n Nature for the paunch manure story.
Organic Control: Neem, citrus oil, and row covers. Garlic spray will often control if applied early and often.
Insight: To help control this pest on susceptible crops, plant them about two weeks later than normal and use large transplants to encourage quick maturity.