CONTROL OF THE FRUIT-TREE LEAF ROLLER AND NOTES ON ITS BIOLOGY IN BRITISH COLUMBIA

The fruit-tree leaf roller, Archips argyrospilus (Walker), overwinters in the egg stage. In 1969, at Kelowna, B.C., the eggs were not affected by winter temperatures of −32 °C. Eggs began to hatch during the half-inch green stage of apple bud development, and hatching was complete by the pink bud stage. Over 50% of the young larvae fed within developing buds where they were protected from direct contact with insecticides. Adults started to emerge in early June, and peak adult activity occurred during 12 June to 19 June. Only one generation was observed during the year. The first overwintering eggs were laid in early June and egg masses were numerous by the end of June.Diazinon, azinphos-methyl, and Gardona® (2-chloro-1-(2,4,5,-trichlorophenyl) vinyl dimethyl phosphate) gave seasonal control of the fruit-tree leaf roller when applied at the pink bud stage. Phosalone did not provide satisfactory control. When diazinon or azinphos-methyl was combined with oil, control was not improved and phytotoxicity occurred to the primary leaves of McIntosh and Spartan apple trees. Gardona® sprayed trees developed damaging numbers of the McDaniel spider mite, Tetranychus mcdanieli McGregor, by mid-July. None of the other treatments affected cither phytophagous or predaccous mites.