Cucumber Beetles

The name cucumber beetle refers to two species: the striped cucumber beetle and  the spotted cucumber beetle, both native insects ranging from Mexico to Canada, though they tend to be most abundant and destructive in their southern range. Cucumber beetles are important pests of cucurbits (cucumber, cantaloupe, winter squash, pumpkin, gourd, summer squash, and watermelon, as well as many other species). They also feed on beans, peas, corn and blossoms of several wild and cultivated plants.

Description

The adult spotted cucumber beetle is about 1/4 inch long with a bright yellowishgreen body. The head, legs and antennae are black and 12 black spots appear on the wings. Adult striped cucumber beetles are about 1/16 inch long, black and yellow in color, and have three longitudinal black stripes on the wing covers. Both have beaded antennae. The eggs of both beetles are orange-yellow and are found in clusters on undersides of host leaves. The larva is about 1/2 inch long with a yellow-white, somewhat wrinkled body andsix long legs.

Damage

Cucumber beetles cause four types of damage: seedling destruction, flower and foliage damage, and root feeding. Damage from cucumber beetles starts in the spring when adults feed on young seedlings. They chew leaves and tender shoots, often girdling stems. They feed on blossoms as well, and late in the season will gnaw holes in the fruit. They are known carriers of bacterial wilt and vectors of cucumber mosaic. Larvae injure plants by feeding on the roots and tunneling through stems.

Control

There are two primary strategies for control of cucumber beetles: row covers will keep beetles off of home plantings until plants are well-established; chemical control is often needed in commercial plantings but is not recommended for home gardeners. 

Adapted from K.A. Sorensen, North Carolina Cooperative Extension Service, 1999