Large-scale, on-site confirmatory, and varietal testing of a methyl bromide quarantine treatment to control codling moth (Lepidoptera : Tortricidae) in nectarines exported to Japan

In total, 30,491 codling moth, Cydia pomonella (L.), 1-d-old eggs on May Gr and nectarines in two large-scale tests, and 17,410 eggs on Royal Giant nec tarines in four on-site confirmatory tests were controlled with 100% mortal ity after fumigation with a methyl bromide quarantine treatment (48 g(3) fo r 2 h at greater than or equal to 21 degrees C and 50% volume chamber load) on fruit in shipping containers for export to Japan. Ranges (mean +/- SEM) were for percentage sorption 34.7 +/- 6.2 to 46.5 +/- 2.5, and for concent ration multiplied by time products 54.3 +/- 0.9 to 74.5 +/- 0.6 g . h/m(3) in all tests. In large-scale tests with May Grand nectarines, inorganic bro mide residues 48 h after fumigation ranged from 6.8 +/- 0.7 to 6.9 +/- 0.5 ppm, which were below the U.S. Environmental Protection Agency tolerance of 20 ppm; and, organic bromide residues were <0.01 ppm after 1 d and <0.001 ppm after 3 d in storage at 0-1 degrees C. After completion of large-scale and on-site confirmatory test requirements, fumigation of 10 nectarine cult ivars in shipping containers for export to Japan was approved in 1995. Comp arison of LD(50)s developed for methyl bromide on 1-d-old codling moth eggs on May Grand and Summer Grand nectarines in 1997 versus those developed fo r nine cultivars in the previous 11 yr showed no significant differences in codling moth response among the cultivars.