Effect of Surround WP on Behavior and Mortality of Apple Maggot (Diptera: Tephritidae)

Abstract

Apple maggot, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), is a key pest in apple (Malus spp.) production areas located in the northeastern and midwestern United States and the eastern provinces of Canada. The development of Surround WP has offered a new approach for controlling apple maggot and other tephritid species, because this material is considered to be compatible with advanced integrated pest management and organic production systems. We conducted studies aimed at identifying the behavioral and biological effects of this material on apple maggots. Specifically, we examined the effect of Surround WP on the visual ecology of adult flies under field conditions, on tactile responses of flies in semifield trials, and on fly mortality in laboratory-based-bioassays. We demonstrated that an even coating of white particles over a fruit-mimicking sphere surface reduced visual attractiveness. We also found that spotty-coated fruit-mimicking spheres (meant to mimic ripe fruit bearing an uneven coating of Surround WP) were perceived by flies as not having the ideal round silhouette shape stimulus. Surround WP served as a tactile deterrent; the residence time of females introduced on to treated fruit was much shorter compared with untreated fruit. Surround WP also had a toxic effect on both adult apple maggot and Rhagoletis suavis (Loew); flies exposed to and forced to stand on Surround-treated surfaces died in <2 d in all trials. The combined effectiveness of Surround WP is based on a reduction in the attractiveness of fruit-based visual cues, an increase in the likelihood of flies leaving treated surfaces due to tactile deterrence, and a potential for increased mortality due to exposure to Surround WP particles.