Phenology, management and effects of Surround on behavior of the apple maggot (Diptera: Tephritidae) in North Carolina

Abstract

Studies were conducted in 2002 and 2003 to evaluate the phenology of the apple maggot, Rhagoletis pomonella (Walsh), in Henderson County, NC, and to compare the efficacy of various products for protection of fruit from maggot infestation. The period of peak trap capture on red spheres differed among orchards, with two orchards having peak captures in early June, and in an abandoned orchard peak capture occurred in late July–September. Surround WP, a particle film kaolin clay product, was evaluated for management of apple maggot at 28.0 kg/ha at two spray volumes (935 and 1870 L/ha) and two application intervals (7- and 14-d). The percentage of apple maggot-infested fruit in Surround treatments, regardless of the spray volume evaluated, was equivalent to that of azinphosmethyl and spinosad treatments. Application of Surround with an airblast sprayer resulted in heterogeneous coverage of fruit within the tree canopy, with higher deposition on fruit on the periphery of trees compared with those in the inner or upper canopy. In choice tests with apple maggot populations in an abandoned orchard, fewer flies alighted on Surround-treated foliage or fruit compared with the water controls, suggesting that the whitish color of Surround-treated trees interfered with visual cues used by flies to locate hosts. In an abandoned orchard with >60% of non-treated fruit infested with apple maggot, the chloronicotinyl compounds imidacloprid (10.0%) and thiacloprid (5.3%) resulted in comparable levels of control to that of azinphosmethyl (8.0%), while spinosad, indoxacarb, and thiamethoxam all had >33% infested fruit. These studies demonstrated that Surround and a number of chloronicotinyl insecticides may be alternatives to azinphosmethyl for management of apple maggot in North Carolina.