Integration of Insecticidal, Phagostimulatory, and Visual Elements of an Attract and Kill System for Apple Maggot Fly (Diptera: Tephritidae)

Abstract

The apple maggot fly, Rhagoletis pomonella (Walsh), is a key pest of apple in eastern North America that has been historically controlled with organophosphate insecticide applications. Here we report on progress toward development of an effective and maintenance-free attracticidal sphere system for this pest species. In our studies, we evaluated lethality of spinosad in combination with a feeding stimulant (sucrose) to replace a Tangletrap sticky coating as the killing agent of a sphere-based behavioral control system. Spinosad was incorporated into cylindrical and contoured controlled-release caps that were fixed atop visually stimulating sphere bases. For both cap styles, spinosad at or near 1.0% (a.i.) proved to be a relatively durable fly-killing agent, providing approximately equal to 85% mortality after simulated rainfall exposure reflective of average season-long precipitation levels experienced during the primary period of risk of apple maggot injury to fruit in the northeastern United States. In field trials, we assessed the impact of color degradation of contoured controlled-release caps on visual responsiveness of apple maggot fly and found that it had no significant impact on captures. In commercial orchard trials designed to evaluate the potential of attracticidal spheres with contoured caps for direct control of apple maggot, a perimeter-based deployment provided protection comparable to plots receiving 1-2 whole-plot insecticide applications.