Strawberry Cultivars Compensate for Simulated Bud Weevil Damage in Matted Row Plantings

Abstract

The strawberry bud weevil (Anthonomus signatus Say; clipper) is considered to be a serious early-season pest in perennial matted row strawberry (Fragaria ×ananassa Duchesne) plantings in North America. Adult females damage flower buds in early spring by depositing an egg in the bud, then clipping the bud from the pedicel. Action thresholds are low (two clipped buds/meter of row) because pest managers and growers have assumed that one clipped flower bud results in the loss of one average-sized fruit. Fields with a history of clipper damage are often treated with insecticides during the first period of warm weather that coincides with inflorescence development, without scouting for clipped buds or evaluating damage. We examined 12 strawberry cultivars and found that most can compensate for a significant amount of flower bud loss, provided that the loss occurs early in the development of the inflorescence. A new threshold is proposed in which the potential loss of fruit per inflorescence is considered, along with the total number of severely damaged inflorescences. We believe that in most circumstances and with most cultivars, clipper injury will remain below the damage threshold.