Colorado Potato Beetle
Colorado potato beetles feasting on potato foliage. Photo: David Grist
These boldly striped beetles and their voracious larvae love to feast on potato plants, skeletonizing the foliage. Often, only the leaf veins remain intact. Colorado potato beetles eagerly consume the foliage of all potato relatives including eggplant, ground cherry, pepper, tomato, and tomatillo, as well as related weed plants.
The yellow-orange beetles are 1/4" long, with black stripes on the wings and black spots just behind the head. The red-orange humpbacked larvae have a row of black spots along both sides of their bodies. The beetles lay distinctive clusters of yellow eggs on the undersides of leaves in the spring.
There may be as many as three generations each year, depending on the region. Adult beetles overwinter 12-18" deep in garden soil or surrounding areas. Today, the Colorado potato beetle occurs throughout the United States except in certain parts of California, Florida and Nevada.
Prevention and Control
- In spring, apply a thick layer of coarse organic mulch — such as straw — around young plants to make it difficult for emerging beetles to reach the plants.
- Prevent adults from laying their eggs by covering plants with garden fabric or pest-control covers before the beetles appear.
- Hand-pick adults at first sign of infestation and drop them into a jar of soapy water. Crush masses of yellow eggs on the undersides of leaves. Crush larvae by hand (wear rubber gloves if you prefer).
- Plant resistant potato varieties, such as King Harry.