Two Scale Insects, Their Bionomics and Control

Abstract

The pine-leaf scale, Chionaspis Pinifoliae Fitch, which infests various pines in private and park plantings and the magnolia soft scale, Neolecanium cornuparvum Thro., which infests magnolias are susceptible to the effects of certain contact insecticides, notably oils. There is a considerable interval of time when the young nymphs of the pine-leaf scale are unprotected by a waxy scale and when they can be hit with a covering spray while the nymphs of the magnolia scale are in a vulnerable condition from October to the middle of April. Satisfactory control of these two scales has been obtained by timely applications of oil emulsions.