What Pest Eats Bush Bean Plants?

Mexican Bean Beetles

• These insects are particularly harmful because both the adult and the larval form feed on the foliage of bean plants. The adult emerges in spring and feeds on the leaves for two weeks before depositing hundreds of eggs on the underside of leaves. The larva also feed on the leaves for up to another 10 days. They pupate and the cycle begins again. Physical removal and insecticide is the recommended treatment.

Japanese Beetles

• The grubs or larva of Japanese beetles will feed on the roots of grass or on vegetable seedlings. Once they become adults, the Japanese beetle feeds on the leaves of plants, starting at the top of the plant. A single beetle poses little threat but Japanese beetles congregate and their numbers are what cause the damage.

Corn Earworm

• As the name suggests, corn earworms prefer corn but will feed on bush beans too. It is the larval form that causes the damage, feeding as soon as they emerge for several weeks. This insect can evolve through seven generations per season depending on climate. Cultural, biological and chemical treatments work best when used together.

Cabbage Looper

• The cabbage looper is a moth whose larval form feeds on leaves for several weeks. The life cycle of this insect is about 25 days, which means four or five generations can develop throughout a growing season. The cabbage looper has many natural enemies and cultural practices can significantly reduce their numbers.

Black Cutworms

• It is the larval form of the black cutworm moth that can create a problem for vegetable plants, including bush beans. The worms live beneath the soil surface, and when the soil is damp, emerge at night to chew the stems of plants. If soil conditions are dry, they attack the plant tissue from beneath the soil. In either case, the plant is destroyed. The instance of black cutworms is occasional and they can be treated with insecticides

Leaf Miners

• The name leaf miner covers a broad range of leaf-eating insects that cause patches or tunnels on leaves. Normally, their presence is not dangerous to the plant unless the populations become significant. Leaf miners have many natural enemies and are normally gone shortly after they appear.

Seed Corn Maggots

• These pests attack seedlings before they have a chance to grow to maturity. The maggots burrow into the seed itself or feed on the emerging cotyledons, stifling the plant's growth. These can be prevented by treating the seeds before planting or buying seed that has already been treated.