Plant Problem Diagnostic
Colorado Potato Beetle: How to Identify and Manage It
The short answer
The Colorado potato beetle adult is a rounded, hard-shelled beetle about 1/3 inch long with ten black lengthwise stripes on yellow wing covers; its larvae are plump, humpbacked, brick-red to orange grubs with rows of black spots. Both feed heavily on potato, and also eggplant and tomato. In a home garden, handpicking is genuinely effective: pick adults and larvae into soapy water, and crush the orange egg clusters on leaf undersides, doing it early and often to prevent later generations.
Because females lay large numbers of eggs and there can be more than one generation a year, staying ahead of them matters more than any single spray. If handpicking cannot keep up on a larger planting, or you are unsure of the identification, contact your local Extension office before escalating.
How to identify Colorado potato beetle
Adults are yellow with bold black stripes; larvae are soft, red-orange, and humpbacked with black spots along each side. Eggs are bright orange ovals laid in clusters on the undersides of leaves.
- Adults about 1/3 inch, ten black stripes on yellow wing covers
- Larvae plump, brick-red to orange, with rows of black spots
- Orange egg clusters on leaf undersides
Least-toxic management, in order
- 1Handpick early — Pick adults and larvae into soapy water, starting when overwintered adults first appear in spring.
- 2Crush egg clusters — Scout leaf undersides and crush the orange egg masses before they hatch.
- 3Scout often — Check plants regularly to break the cycle before a second generation builds up.
- 4Encourage natural enemies — Predators and parasites help; avoid broad sprays that remove them.
When to escalate
On larger potato plantings where handpicking cannot keep pace, targeted least-toxic products may be needed, and these beetles are known for developing resistance, so rotating approaches is wise. Contact your regional Extension office for current guidance before applying any product.
→ Colorado potato beetle can produce multiple generations per season in warmer regions, so early, persistent removal of the first generation pays off.
Sources
Reviewed 2026-07-18. We cite university Extension, government, and established horticultural sources — and never invent pesticide rates or dangerous treatments.
- University of Minnesota Extension — Colorado potato beetle — Adult and larval appearance, egg clusters, and handpicking into soapy water
- UMass Extension — Colorado Potato Beetle Management — Lifecycle, multiple generations, and crushing eggs, larvae, and adults early to prevent later generations