University of Illinois Extension
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Colorado Potato Beetle
Potato and Pepper


The Colorado potato beetle attacks other solanaceous plants in addition to potatoes. The Colorado potato beetles overwinter as an adult under the debris along the field edges. In Illinois, the adults can be active in mid-spring. The adult population starts to develop in mid-April and becomes a problem as the time goes on until the middle of July. The second generation appears in late July to the end of August. Both the adult and larvae feed on the leaves and may completely defoliate the plant. Female lay reddish-orange eggs on the underside of the leaves in masses. The peak egg-laying periods occur in mid-June but may occur in May when the temperatures are high in early spring. The emerged larva first feeds on the younger leaves and later moves on to older leaves. The larva pupates in the soil to the adult stage. The whole life cycle from egg to adult occurs in less than 3 weeks.


Crop rotation reduces and delays infestation in spring, locate field far away (700-800 yards) from overwintering sites, and control the larvae by spraying with insecticides recommended in your state. Home gardeners should try row covers on small gardens.


Colorado potato beetle