Evaluation of Unbaited Pyramid Traps for Monitoring and Controlling Plum Curculio Adults (Coleoptera: Curculionidae) in Apple Orchards

Abstract

We investigated unbaited black pyramid traps, placed on the ground, for monitoring overwintered adult plum curculios, Conotrachelus nenuphar (Herbst), in eight large commercial apple orchards in Massachusetts. None of the trap positions for any tree size in any orchard showed a significant positive relationship between the temporal occurrence of adult captures from petal fall until 4 to 5 wks afterward and the temporal occurrence of adult-initiated ovipositional injury to developing fruit during the same period. The amount of adults captured by traps was not significantly related to the amount of injury to fruit caused by adults, either across the entire period of overwintered adult activity or within periods of adult activity before, between or following insecticide applications. Similar traps placed next to trunks of groups of four adjacent trees in a small unmanaged orchard or next to trunks of every tree in a small commercial orchard failed to provide detectable or commercially-acceptable control of plum curculio. An alternative to unbaited pyramid traps on the ground is needed to effectively monitor or control plum curculio in apple orchards in Massachusetts.