WSU Extension


Strawberry : Root weevils
(revision date: 6/8/2015)

Several species of root weevils are common pests of strawberries. Adults are typically brown to black in color and may have lighter markings on the back. They range in size from 1/5" to 1/3" in length. These beetles cannot fly. Adults cause minor damage to plants by chewing ragged notches in the leaf margins. However, the most serious damage is done by the larvae. They are curved, legless, and white or pinkish with darker heads. They are found in the soil, where they feed on the roots. Severe root damage can occur, resulting in wilting and death of plants. Root weevils generally overwinter in the soil as larvae, with adults emerging in spring to early summer. Root weevil adults typically feed at night and spend the day at ground level.
Management Options

Non-Chemical Management
  • Hand-pick and kill night-feeding adults, when practical.
  • Cultivate future planting sites in the fall to reduce numbers of overwintering root weevils.
  • Control weeds in and around plantings. Weeds may serve as other hosts for root weevils.
  • Heavily damaged plantings should be destroyed.
  • Beneficial nematodes may be purchased at some garden centers. They are only effective if soil temperatures are warmer than 53 degrees F. The soil must be moist prior to application and for several days afterward. Do not apply nematodes in direct sunlight, since ultraviolet light quickly kills them.
Select non-chemical management options as your first choice!

Chemical Management

Apply at night when adult weevils are feeding. Use a flashlight at night to determine where this activity has begun. Entomophagous nematodes (available through some nurseries) have proven useful. Nematodes are sensitive to UV light. Do not apply in direct sunlight. Apply nematodes only in late summer or early fall to very wet soil when soil temperatures are above 52 degrees F.

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Caption: Root weevil damage on strawberry
Photo by: A.L. Antonelli
Caption: Root weevil larvae
Photo by: A.L. Antonelli
Caption: Root weevil adult
Photo by: A.L. Antonelli