iage in its
earlier stages consists of irregularly shaped yellowish areas which turn
brown when the tissues die.

[15] ~Melanocallis caryaefoliae~ (Davis).

This aphid is usually controlled with nicotine sulfate (40 percent
nicotine), 3/8 pint plus summer oil emulsion, 2 quarts per 100 gallons
of spray. Parathion and benzene hexachloride have given good results in
experimental work but are not yet generally recommended.

~Pecan phylloxera.~ The pecan phylloxera[16] is related to aphids. It
attacks principally the vegetative parts of the tree such as the leaves,
petioles, and shoots on which galls (Fig. 6) are produced. Pecans,
hickories, and other species of nuts are subject to infestation.

[16] ~Phylloxera devastatrix~ Perg.

In the past a spray of nicotine sulfate (40 percent nicotine) 13 ounces
combined with either lime-sulfur solution, 2-1/2 gallons per 100 gallons
of water, or lubricating-oil emulsion, 2 quarts per 100 gallons, applied
in the late dormant period has been the standard recommendation. In
recent experiments in the South with some of the new organic sprays,
benzene hexachloride and some of the dinitro compounds have indicated
good promise.

~Fall webworm,~[17] ~walnut caterpillar,~[18] ~and hickory tussock
moth.~[19] The caterpillars of these species (Figs. 7, 8, 9) are
frequent pests on the foliage of nut trees. They often defoliate entire
branches.

[17] ~Hyphantria cunea~ (Drury).

[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