Harmful Insects in Vegetable Gardens

Home gardeners will inevitably encounter insect inhabitants in their vegetable gardens. While not all insects are harmful to your garden, it is important to be able to identify the most common pests.

Aphids, or plant lice, live in colonies and feed on most garden plants. They are generally between 1/32 to 1/8 of an inch in length and can be brown, green, yellow, pink or black. Plants such as mint, garlic, chives, coriander and anise discourage aphids from colonizing.

These insects are white and about 1/25 of an inch long. Their nymphs live on the underside of leaves and are green, flat oval-shaped and the size of a pinhead. White flies feed on tomatoes, potatoes, eggplant, melons, beans, cucumbers and squash. This insect can be discouraged by planting marigolds and nasturtium.

According to the Department of Entomology and Nematology at the University of Florida, Leafminers are the most common harmful vegetable garden insects. They lay their eggs on most vegetable plants, and their larvae live between leaf surfaces. They are identifiable by the snake-like tunnel patterns they carve into leaves.

Hornworms feed on eggplant and tomato plants. They are green caterpillars with white stripes and horn-shaped protrusions at their ends. Hornworms can reach 3-1/2 to 4 inches in length, and as adults will eat away plants' foliage. They are discouraged by marigolds, sage and borage.

These moths' larvae feed on cabbage, cauliflower, collards and broccoli. They grow to about 1/3 of an inch long and are pale yellow-green in color. The male moth has three yellow diamond-shaped marks on its back.

Earworms are caterpillars that bore into bean and pea pods, the silk ends of corn ears and tomato fruits. They have yellow heads and black legs, with abdomen and thoraxes colored brown, green, pink, yellow or black. Earworms grow from 1 to 1 1/2 inches in size.