Abstract

The standard spray schedule provides for the control of the more important apple insects. It displays some weaknesses against certain species during seasons when weather conditions prevent timely applications. Investigations have been conducted to find materials or practices that will amplify present means of control of rosy aphids and bud moth. Three methods have been tested; viz., (1) autumn defoliation, (2) fall spraying, and (3) winter treatment. Sodium nitrate proved the best material for rendering the trees unattractive to the rosy aphid, and apparently is safe to the twigs. None of the defoliation materials controlled bud moth. Fall spraying with nicotine or ground tobacco killed the fall migrants and the egg-laying females of the rosy aphid, but the utility of this means of control remains to be determined. Winter treatment with tar distillate sprays were very effective against apple aphid eggs and the nymphs of the spruce gall aphid, but proved ineffective against the eggs of the leaf roller. These washes appear to be safe to the trees . As regards rosy aphid, these methods of treatment, if successful, may prove of value in that the period of spraying could possibly be extended.

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