Colorado Potato Beetle
Pest · Commonly affects: Potato, Eggplant, Tomato, Pepper, Tomatillo, Ground cherry
The Colorado potato beetle (Leptinotarsa decemlineata) is a striped leaf-eating beetle and the most notorious insect pest of potatoes across the United States. It matters to home gardeners because both the adults and their larvae feed heavily on nightshade-family foliage and can strip a small planting in just a few days.
How to identify it
Adults are rounded, hard-shelled beetles about three-eighths of an inch long with ten narrow black stripes running lengthwise down the yellow-to-tan wing covers, plus a yellow-orange head marked with black spots. The larvae are the real giveaway: plump, humpbacked, and brick-red to salmon-orange with a black head and two rows of black dots along each side. Look on the undersides of leaves for tight clusters of bright orange-yellow, football-shaped eggs, which are usually the first sign before feeding damage appears.
Damage
Adults and larvae chew ragged holes in leaves and can defoliate plants entirely, with the larvae causing the bulk of the injury as they grow. Heavy feeding during flowering and tuber formation robs the plant of the leaf area it needs to produce a crop, which cuts potato yields sharply and stunts or kills young or stressed plants.
Prevention
Rotate potatoes and their relatives to a bed well away from where nightshades grew last year, since the adults overwinter in the soil and emerge in spring right where they fed before. Space and water plants for steady, vigorous growth so they can better tolerate some feeding, keep the garden and its edges free of volunteer potatoes and nightshade weeds that host the beetle, and favor early-maturing varieties that can bulk up before beetle numbers peak. A thick straw or organic mulch over healthy soil makes it harder for emerging adults to reach plants and shelters the ground beetles and other predators that feed on them.
How to manage it
Scout plants often and handpick adults, larvae, and egg clusters, dropping them into a jar of soapy water or crushing the orange egg masses on leaf undersides; catching the first spring beetles before they lay eggs pays off the most. Cover young plants with floating row covers anchored at the soil line to block adults from ever reaching the foliage, keeping in mind that potatoes and tomatoes do not need insect pollination so covers can stay on through much of the season. Encourage natural enemies such as the spined soldier bug, lady beetles, lacewings, and parasitic tachinid flies by keeping mulch and flowering plants nearby, and prune off and remove badly chewed or egg-laden leaves to lower the next generation.
General guidance for US home gardens, focused on prevention and non-chemical control. For a confirmed diagnosis and options specific to your area, contact your local Cooperative Extension office. Page updated Aug 4, 2026.