Plant Problem Diagnosis Key / Pests
Colorado potato beetle
Leptinotarsa decemlineata
An oval yellow beetle with ten black stripes that defoliates potato, eggplant and sometimes tomato. Its plump, red-orange larvae with black spots do most of the feeding.
Signs
- Clusters of bright yellow-orange eggs under leaves.
- Hump-backed red larvae with two rows of black spots, eating leaves to stems.
- Striped adults; populations resist many insecticides.
What favors it
Fields planted to potato, tomato or eggplant the year before; adults overwinter in the soil of last year's field and its edges.
Prevention
- Rotate at least 1/4 mile from last year's potato or eggplant ground.
- Thick straw mulch at planting slows beetles and favors predators.
- Row cover before the beetles appear.
Crops it shows up on
Potato; Tomato, pepper & eggplant.
Often confused with
Sources
- Colorado potato beetleUniversity of Minnesota Extension
- Colorado Potato Beetle on VegetablesUniversity of Maryland Extension
Treatment by crop
Cultural, biological and chemical options in the order to use them, and notes written for each crop.
Identification is free. Treatment is on the Home and Pro plans.
Questions in the key that lead here
- Look the plant over, leaf undersides included. Are insects, mites, slugs, eggs, webbing or droppings on it?
Yes, something living or its traces - What is on the plant?
Small insects, clustered or flying - Do they fly up when the plant or the soil is disturbed?
No, they stay put or crawl - What kind of insect?
Hard-bodied beetles - Which beetle?
Yellow with black stripes, rounded
Not a match? Start the key or describe what you see.
More photos
More from university Extension: search Extension pages on colorado potato beetle, or find a plant diagnostic lab through your state's Extension.
Other pests
- Aphids
- Bagworms
- Bark beetles of pine and spruce
- Broad mites and cyclamen mites
- Caterpillars
- Cicada and twig-cutting damage
- Cucumber beetles
- Cutworms
- Elm leaf beetle
- Emerald ash borer
- Flea beetles
- Fungus gnats
- Galls on leaves and twigs
- Hemlock woolly adelgid
- Japanese beetles
- Lace bugs
- Leafminers
- Mealybugs
- Pine sawflies
- Root aphids
- Root-knot nematodes
- Russet mites
- Sapsucker damage
- Scale insects
- Shore flies
- Slugs and snails
- Spider mites
- Spongy moth (gypsy moth)
- Spotted lanternfly
- Squash bugs and stink bugs
- Squash vine borer
- Tent caterpillars and fall webworm
- Thrips
- Whiteflies
- Wood borers