Management of the Apple Maggot, Rhagoletis pomonella (Walsh) (Diptera: Tephritidae), in Disease-Resistant Dwarf and Semi-Dwarf Apple Trees

Abstract

Management programs for the apple maggot (AM), Rhagoletis pomonella (Walsh), were tested in small orchards of dwarf and semi-dwarf, disease-resistant apples in New York State. These orchards were exposed to severe AM pressure from nearby unsprayed apple and hawthorn trees. In the Hudson Valley, a standard six-spray schedule of azin-phosmethyl applied every 14 days from June to mid-August reduced AM damage to 1.4% in 1979, and in 1980 a reduced two-spray schedule of azinphosmethyl at the beginning and peak of adult activity gave similar control (1.3% damage). In an adjacent plot, a nonconventional control program of trapping AM flies on red sticky spheres was about as effective (1.0% damage) as the azinphosmethyl program in 1979, but allowed more damage (4.9%) in 1980 than the reduced insecticide schedule. At Geneva, plots treated with carbaryl starting 10 days after AM emergence and thereafter at 14-day intervals during adult activity had 5.7 and 0.4% infested fruit, respectively, during 1980 and 1981. Carbaryl applications in other plots based on Pherocon AM trap catches or fruit maturation were less effective. Sphere trapping programs at Geneva which had 12.8 and 2.9% infested apples, respectively, during 1980 and 1981, were also slightly less effective than the standard protective carbaryl schedules.