(Photo: adult beetles and larvae feeding)
Colorado Potato Beetle
Tis the season of the Colorado potato beetle: May, June, and early July. Although these insects prefer potato plant leaves, tomato, eggplant, and pepper plant leaves are also on the menu! I have seen them at work on all four plant varieties in various gardens in Ottawa.
Look for the black striped adult beetles, the tan to red/brown larvae, and the bright orange egg clusters under the leaves.
Delaying planting until mid June can help you avoid the bug rush, as the adults are the travelers that deposit eggs, stay on the plant, and strip it bare. They leave what looks like an umbrella with no fabric.
(Photo: Adult Colorado Potato beetles, larvae, and egg clusters)
If you have an infestation, an organic defense involves hand picking and squishing them (gloves may help), drowning them in soapy water (used dish water may be useful), or spraying them with soap and water (40 parts water to one part soap – a tip from radio gardener Ed Lawrence. Rinse the plants 10 minutes after spraying them, and repeat the procedure every three days until the beetle population disappears. Next season, do not plant members of this plant family in the same spot – if the garden is not very large, skip a year. Try other vegetables and herbs instead.
Tip: a spray pistol on a flexible tube attached to a bottle is better than a spray bottle with the pistol attached to the bottle. You need to aim the pistol in many directions to spray over and under the leaves while the bottle sits on the ground.
(Photo: Beetle devastation in just one week)
If your seed potatoes or seedlings are far advanced and you must plant, try row covers immediately when you plant the potatoes. Do check each day to be sure you have not created a bug incubator – this happened to me at a community garden. A regimen of hand squishing (Adults are armor plated and the spray is best on the larvae and the eggs) and spraying every three days for 2 weeks with soap and water led to victory, but it was a lot of work. The next season, I planted beans.
An alternative is to plant in containers for one year in a different location. Consider patio potato bags, large pots, box beds, and cold frames.
Happy Gardening!
