Cucumber Beetles

If you have ever grown cucumbers in your vegetable garden, then you have probably ran across the cucumber beetle. If you have grown cucumbers before and never seen cucumber beetles on your plants, then you are lucky. I have lost entire plants due to this pest insect.

This little insect can be one heck of a nightmare for your cucumber plants. Here’s some information on identifying cucumber beetles, what they do to your cucumber plants, and some ways to prevent and eliminate them in your garden.

What Is A Cucumber Beetle?

Adult beetles are shiny with black heads, long antennae, and about a quarter-inch long. Larvae are whitish and slender with three pairs of short legs; the head and tip of the abdomen are darker. Adults may be striped or spotted, depending upon species.

There are two main types of cucumber beetle – striped and spotted. The spotted cucumber is greenish yellow and has twelve black spots on its back. The striped cucumber beetle is yellowish orange and has three black stripes on its back. Do not confuse cucumber beetles for ladybugs, but can be distinguished by the antennae. Ladybug antennae are short and stubby, while those of the cucumber beetle are long and threadlike.

Larvae of the spotted cucumber beetle feed on the roots of corn, small grains, beans, sweet pea, and several grasses but do not usually cause noticeable damage in gardens. The striped cucumber beetle larva feeds exclusively on cucurbit roots and can damage these crops when infestations are heavy.

Beetles overwinter as adults in weedy areas and move into planted fields and gardens as soon as plants start to come up. They lay their yellow orange eggs at the base of plants or in soil cracks. Hatching larvae burrow into the ground seeking out roots, feed for 2 to 6 weeks, pupate, and emerge as adult beetles that attack the aboveground portions of the plant. There are several generations a year. The most common predators of cucumber beetles are ladybugs, lacewings, assassin bugs, solider beetles, and spiders.

Damage Caused By Cucumber Beetles

Adults feed on the leaves of many vegetables as well as on soft fruit. Shoots and blossoms may also be consumed. Cucumber beetles may also spread cucumber mosaic virus or wilts in cucurbits. Larvae feed exclusively on roots, but do not generally damage vegetable garden plants, although corn may occasionally be damaged.

Controlling Cucumber Beetles

One of the best things you can do to prevent cucumber beetles is to take steps in order to prevent them. Monitor your plants – all of them. Don’t let the name fool you, cucumber beetles will eat a wide variety of plants including sunflowers, pumpkins, and melons.

Controlling of cucumber beetles is difficult. Most older plants can support substantial numbers without serious damage. The best strategy for most vegetable gardens may be to place protective cloth over emerging plants and remove it when plants are old enough to tolerate damage. Use organic pesticides for very bad infestations or a use a good cucumber beetle trap.