PECAN BUD MOTH
The pecan bud moth, Gretchena bolliana (Sling.), damages nursery stock and freshly top-worked pecans. The greenish larvae feed in the axils of the newly set buds and in the terminals of young trees, causing extensive branching. There are several generations each year.
Figure 21. Moth of the pecan catocala.
Control.—This insect may be controlled by applying a spray containing 2 pounds of 50 percent DDT wettable powder per 100 gallons of water.
TWIG GIRDLER
The adult twig girdler, Oncideres cingulata (Say) (O. texana of some authors), girdles twigs and branches, weakening them so that they fall off or die on the tree, [Figure 22]. This insect is active during the late summer and early fall. Many twigs may be found on the ground under a severely infested tree. Secondary branching may occur and the number of bearing twigs is reduced.
The twig borer is a grayish brown beetle one-half to five-eighths inch in length with a broad gray band over the middle of the wing covers. Its head is reddish brown and bears a pair of long antennae, which extend beyond the abdomen on the male.
The larva is a white legless grub about three-fourths inch long when it reaches maturity.
This insect overwinters as a partially grown larva in a twig on the tree or ground. It develops rapidly in the spring feeding in the twig. Following pupation, the adult emerges in late August or early September. The female systematically girdles twigs and deposits eggs in the severed portion since the larva is unable to develop in healthy sapwood. The eggs hatch in a few weeks into larvae which remain small until the following spring when they complete development, pupate and emerge as adults in the late summer and fall. There is one generation annually, although some individuals require 2 years to mature[1].