[18] ~Datana integerrima~ (G. and R.)
[19] ~Halisidota caryae~ (Harr.)
The best time to apply control measures is as soon as possible after the caterpillars hatch. The insects can be readily destroyed with lead arsenate, 3 pounds, or DDT (2 pounds) of 50 percent wettable powder, per 100 gallons, applied when they appear. Other new organic insecticides may also be effective but have not been widely tested.
~The rose chafer and Japanese beetle.~ Adults of the rose chafer[20] (Fig. 10) and the Japanese beetle[21] are voracious feeders on the foliage of nut trees and must be destroyed if severe injury is to be avoided.
[20] ~Marcordactylus subspinosus~ (F.).
[21] ~Popillia japonica~ Newm.
Fortunately these insects may now be controlled by spraying with DDT, 2 pounds of 50-percent wettable powder per 100 gallons of water, when the beetles appear. In the case of the Japanese beetle a second application may be necessary if the infestation is heavy.
~Spider mites.~ Nut trees, especially those which have been sprayed with DDT, may become seriously injured by various species of mites.[22] DDT is very toxic to the natural insect enemies of plant-feeding mites and therefore the mites build up to injurious numbers.
[22] ~Tetranychus~ sp. and others.
Of the various miticides recently tested on pecan, a spray of parathion was the most promising. In some recent tests for the control of spider mites on chestnut trees, 1-1/2 pounds of 15 percent parathion wettable powder per 100 gallons of water was effective. Do not use parathion unless you observe all the precautions contained on the package label of the material.