until the first weevils
appear. Then jar all trees at weekly intervals until about the middle of
September, when egg laying will have been largely completed.

The butternut curculio[11] attacks native butternuts and introduced nuts
of a similar type. It passes the winter as an adult in trash or other
shelter it can find in the vicinity of nut trees. It is a small,
hard-shelled, rough-backed snout beetle. Late in the spring it makes its
way to the trees, and lays eggs in the young shoots. On hatching, the
young larva penetrates into the young shoot or leaf stem or nut and
feeds there, causing the leaf or nut to dry up and fall off. Upon
completing development in the fallen leaf or nut, the mature larva
enters the soil. After a month or so in the ground the adult emerges,
feeds on the foliage for a while, and then enters hibernation. There is
but one generation a year.

The black walnut curculio[12] is similar to the butternut curculio in
seasonal history, but it attacks principally the fruit of the black
walnut and butternut, apparently preferring the former.

The hickory nut curculio[13] is much like the preceding two species, but
it attacks chiefly partly grown hickory nuts, causing a heavy dropping
in midsummer.

The hickory shoot curculio[14] attacks chiefly the shoots of various
kinds of hickory. The damage is seldom of much importance except to
newly transplanted trees. On pecan it attacks the unfolding buds and
shoots. Pecans most commonly attacked are those that are uncultivated or
are adjacent to woodlands containing native pecan and hickory trees.

For many years these curculios have been controlled by spraying the
trees soon after growth starts with lead arsenate, 2 pounds per 100
gallons, plus an equal amount of hydrated lime. One or two additional
applications may be needed as new growth appears or as the nuts increase
in size. Recent experimental work indicates that BHC or lindane may be
more effective for controlling these insects. A spray containing 3 or 4
pounds of technical BHC (10-percent gamma) or 1-1/2 to 2 pounds of
25-percent lindane wettable powder per 100 gallons, applied when the
buds show from 1/4 to 1 inch of green growth or when jarrings show
adults are present, has given fairly good control.

Walnut Husk Maggot

The walnut husk maggot[15] attacks black and English walnuts,
butternuts, and a few other nuts. The feeding of the larva, or maggot,
in the husks impairs the quality of the