Recognize Colorado potato beetle

• Adults: Oval-shaped beetles (8–12 mm) with distinctive yellow wing covers marked by 10 black stripes. Easily visible on potato plants, often present in large numbers.
• Eggs: Bright yellow to orange, laid in clusters on the underside of leaves in spring and early summer.
• Larvae: Plump, reddish-orange grubs with two rows of black spots on each side. They are voracious feeders, capable of defoliating potato plants rapidly.
• Pupae: Found in the soil, orange to reddish in color, where larvae transform into adults. This stage is hidden but critical for biological control strategies.

Life cycle

• Eggs are laid in spring on host plants.
• Larvae hatch within a week and pass through four instars, feeding heavily on leaves.
• Pupation occurs in the soil, after which new adults emerge to continue feeding and reproduction.
• Overwintering: Adults burrow into the soil to survive winter, emerging the following spring.

Colorado potato beetle damage

Both larvae and adults of Colorado potato beetle cause severe leaf damage, often leading to complete defoliation if uncontrolled. This reduces tuber development and can cause yield losses of up to 100% in heavily infested fields. The pest’s ability to rapidly develop resistance to insecticides makes long-term control particularly challenging.

Prevention

• Monitor fields regularly for egg masses and young larvae.
• Practice crop rotation to reduce overwintering populations.
• Use trap crops or resistant potato varieties where available.
• Integrate biological control to reduce reliance on chemicals.

Control Colorado potato beetle

The most effective and sustainable way to control Colorado potato beetle is by applying beneficial nematodes. These microscopic organisms naturally occur in soil and are highly specialized predators of soil-dwelling insect stages. Once applied, nematodes actively search for pupating larvae and overwintering adults, penetrate them, and release symbiotic bacteria that quickly kill the host. After reproducing inside the host, new nematodes are released into the soil to continue the cycle, providing ongoing protection.

The beneficial nematode product Capsanem (Steinernema carpocapsae) is particularly effective against Colorado potato beetle. It targets larvae and adults in the soil, reducing populations before they emerge to infest crops.

For best results:

• Apply when larvae are pupating in the soil or when adults are overwintering.
• Ensure soil moisture before, during, and after application to help nematodes move effectively.
• Apply during evening or cloudy conditions to avoid UV sensitivity.

With correct timing and application, Capsanem provides growers with a safe, reliable, and natural solution to reduce Colorado potato beetle populations and protect potato yields.