STINK AND PLANT BUGS
The adults of several species of stink bugs and plant bugs suck the sap from young pecan nuts causing an injury known as black pit, in which the interior of the nuts turns black. The injured nuts fall from the trees before the shells harden.
Feeding by the insects after shell hardening, [Figure 14], produces brown or black spots on the kernels. Areas affected taste bitter, but the remainder of the kernel is unaffected.
Stink bugs are familiar to everyone. Plant bugs resemble them and are usually shades of brown, smaller and narrower in body outline.
Plant bugs and stink bugs overwinter in the adult stage in debris on the ground. In the spring, the adults are attracted to growing vegetation such as cover crops or weeds, where they deposit their eggs. The immature bugs develop on low-growing vegetation. When they reach maturity, their wings are fully developed and they fly to pecan trees. A few eggs may be deposited on pecan trees, but the young bugs apparently are unable to develop on them. Only the adults are present in sufficient number to inflict economic injury. There may be as many as four generations each year.
Control.—Although certain insecticides will control these pests, the number and frequency of spray applications necessary for control would not be economical.
Care should be taken to keep weeds down in the orchard during the growing season. Winter cover crops should be plowed down early in the spring so they will not be attractive to the adults coming out of hibernation. If this operation is delayed, the bugs will leave the cover crop when it is removed and migrate to the trees in large numbers.