Colorado Potato Beetle

The Colorado potato beetle (Leptinotarsa decemlineata) is a major potato pest throughout North America. It can also feed on eggplant, tomatillo, and related crops. The adults become active in the spring at about the same time potatoes emerge from the ground. If you have had these pests in the past, you know that the larvae and adults feed on the leaves and can completely defoliate the plants. Unfortunately, many pesticides are ineffective on this insect as they have developed resistance to the chemicals.

The first step is always correctly identifying the insect. The adults are approximately 3/8” long, oval, have a yellow-orange prothorax (area behind the head), and yellowish-white wing clusters with 10 narrow black stripes. Adults will overwinter 5-10 inches underground in field margins, windbreaks, and gardens. The larvae go through a couple of different colors before becoming adults. When they first hatch, they are brick red with black heads and slowly transition to a pink or salmon color with black heads. All larvae have two rows of dark spots on each side of their bodies. Controlling potato beetles requires a combination of methods. Constantly monitor your plants to catch the issue early. Cultural controls include removing nightshades and ground cherry plants near your garden, mulching between beds, and planting an early-maturing potato variety. If you have significant issues, stop planting potatoes for a couple of years, as potato beetles aren’t very mobile. I also recommend using a row cover to prevent feeding and picking off any adults you find, putting them in a bucket of water, and crushing any eggs you see. I also try to encourage populations of lady beetles and stink bugs in your garden as they feed on the potato beetle.

 

Have questions? Contact our office where our Horticulture Extension Agent will assist you with questions.

Phone: (316) 321-9660

Email: callae@ksu.edu