The Use of Petroleum Oils as Insecticides: III. Oil Deposit and the Control of Fruit Tree Leaf roller and Other Apple Pests1

Abstract

In earlier papers of this series (Pearce, et al. 1941; Chapman et al. 1941) the writers have described a method of determining the quantity of oil deposited on apple bark in spraying and have considered the more, important factors affecting deposition. We present in this article data showing the relation of these deposits to insect control. The fruit tree leafroller, Cacoecia argyrospila Walker, was the principal insect utilized although some data were obtained on the apple red bug, Lygidea mendax Reut. and the rosy apple aphid, Anuraphis roseus Baker. These experiments were conducted under field conditions using mature apple trees. Test materials were applied with standard orchard spraying equipment and except as indicated, all spraying was done in the spring while the trees were still dormant.