If you grow potatoes anywhere from the Rocky Mountains to the East Coast, you probably have run into the Colorado potato beetle. This beetle loves not only Irish potatoes, but eggplant and other nightshades as well. The large adult beetles, which are orange with black stripes, feed on potato leaves and lays orange-yellow eggs in clusters under the leaves. The eggs hatch into soft, red larvae that really chow down on your plants.
Colorado potato beetles are the perfect insect pest for kids to help control in the garden. These large, colorful insects are easy to find. Even their eggs are obvious if you look under the leaves. One of the best control mechanisms is squishing the eggs, larvae, and adults. This activity can send young kids into a frenzy. Some kids will use rocks to crush them, while others will place them in pails of soapy water to kill them. Still others will be brave and squish them with their fingers. While all this squishing is good for the garden and exciting for the kids, you can also use this pest as a learning tool. Talk to your kids about the life cycle of potato beetles. Have them examine the different stages of growth. Explain that the larval stage is the most destructive because the larvae are growing the fastest. Ask what you think will happen to the beetles if you kill most of the eggs. Ask where you think the adults overwinter (usually in plant debris in the soil near the garden).
Based on this information, have your kids discuss the best ways to control the beetles. Handpicking works, but you can also plant resistant potato varieties such as ‘King Harry’, which has hairy leaves the beetles don’t like laying eggs on. Removing nightshade weeds, covering young plants with row covers to prevent the adults from laying eggs, and applying organic sprays such as Bacillus thuringiensis tenebrionis all help. Explain that these targeted sprays work best on the larval stage and don’t harm pets, humans, or beneficial insects.