Relative Efficacies of Sticky Yellow Rectangles Against Three Rhagoletis Fly Species (Diptera: Tephritidae) in Washington State

Sticky yellow rectangle traps are used to monitor various pest Rhagoletis flies (Diptera: Tephritidae), but it is unclear if relative efficacies of these traps differ with fly species.  Here, the major objective was to identify the most efficacious of five commercial sticky yellow rectangles baited with ammonium carbonate against western cherry fruit fly, R. indifferens Curran, apple maggot fly, R. pomonella (Walsh), and walnut husk fly, R. completa Cresson, in Washington state, U.S.A.  Two plastic yellow sticky strips (YSS) supplemented with Tanglefoot adhesive (TF), the AGS-YSS + TF and OS-YSS + TF, and three sticky yellow cardboards, the Pherocon AM, Multigard AM, and AlphaScents (AS) Yellow Card, were tested.  Across all three species, the AGS-YSS + TF and OS-YSS + TF generally caught the most flies, the AS Yellow Card caught more than the Pherocon AM, and all caught more than the Multigard AM.  Adding TF to the Pherocon AM did not make the trap as effective as the AGS-YSS + TF against R. indifferens, but it did against R. pomonella and R. completa.  Results suggest the plastic YSS + TF rectangles tested here are better than standard cardboard rectangles for capturing high numbers of all three Rhagoletis species, implying they should be the rectangles of choice for monitoring these flies.  Results also suggest that similar trap efficacies against the three species may have different underlying causes.