Oviposition Patterns of the Strawberry Bud Weevil (Coleoptera: Curculionidae) at Two Spatial Scales and Implications for Management

Abstract

The strawberry bud weevil, Anthonomus signatus Say, is an important pest or strawberries in eastern North America. Typically, growers treat entire fields with insecticides on an annual basis when the number of clipped buds exceeds a threshold. The 3 objectives of this study were as follows: (1) to determine the distribution of weevil injury within strawberry fields, (2) to determine if managing only field borders would be effective, and (3) to determine if weevils preferentially oviposit in particular orders of flowers on an inflorescence. During a 3-yr monitoring period (1992-1994), A. signatus oviposition activity increased unidirectionally at a rate of ≈8 m or 10 rows (1.25 m centers) per year. In 7 grower fields in New York, only the 12-m perimeter of strawberry fields treated with insecticide reduced injury to a level similar to interior portions of the field. In the interior of these fields, insecticide treatments did not influence the level of weevil damage. Even when weevils damaged floral buds, only a small proportion (7%) were primary flowers that produce the largest fruit. On average, oviposition occurred disproportionally in secondary flower buds. These observations indicate that A. signatus can be managed effectively by treating the outside perimeter of fields rather than entire fields, planting cultivars that compensate the most for clipper injury on the perimeter, and suggest that thresholds could be raised because damage to large, primary buds is limited.