The immature larva is brown, but changes to dark green as it develops to a length of one-half inch. It has a shiny, brownish black head and is enclosed in a gray case which completely covers the body and is borne in a position nearly perpendicular to the leaf on which the larva is feeding.
The pecan leaf casebearer overwinters as an immature larva in a hibernaculum around a bud. It emerges in late March or early April as the buds open. The larvae mature in April, May and June and transform into pupae within their gray cases, [Figure 15]. The moths are present from May until early August. Eggs are deposited during this period on the underside of the leaves. The larvae which hatch from these eggs develop slowly, and do not attain a length of more than one-sixteenth inch during that season. They construct little winding cases in which they live. Their feeding produces irregular blotches on the leaf surface, [Figure 16]. Before the leaves drop in the fall, the larvae migrate to the buds, and construct their overwintering hibernacula. Only one generation is completed each year.
Control.—Control of this insect is accomplished by spraying for the pecan nut casebearer. See spray schedule, [page 4]. The insecticides recommended for nut casebearer control also reduce infestations of the leaf casebearer.
Figure 15. Overwintered larvae of pecan leaf casebearer in their cases.
Figure 16. Summer injury to the leaves by the pecan leaf casebearer.
PECAN PHYLLOXERA
The pecan phylloxera, Phylloxera devastatris Perg., and the pecan leaf phylloxera, P. notabilis Perg., produce galls on the new growth of pecans. Leaves, twigs and nuts may be affected.
The galls are conspicuous swellings, [Figure 17], which attain a size of from one-tenth to 1 inch in diameter. They are caused by a soft-bodied insect which is closely related to aphids.