Several species of boring beetles are attracted to pecan trees. Although most attack trees that are damaged, wounded or ailing, some beetles will also attack healthy young wood and foliage. In addition to eating tree tissues and laying larvae, they carry diseases such as fungi and viruses on their limbs. The beetles spread the diseases when they're on a tree and when they go from tree to tree. Effective control entails keeping the tree in peak health and unattractive to pests, regularly clearing the surrounding soil, manually removing beetles and erecting physical barriers to prevent beetles from reaching a tree.
Maintain healthy pecan trees that are not stressed for water or nutrients. Feed twice a year, in February and June, with a pecan tree fertilizer with a guaranteed analysis of 10-10-10 plus zinc. Water deeply to keep soil moist to a depth of roughly 4 inches.
Pull up all weeds and other plants and clear away all tree litter from around the base of the tree out past the drip line. The goal is to get rid of breeding grounds for beetle larvae and the diseases they spread. If weeds are too thick to pull, treat the area with an herbicide applied according to the label directions.
Remove beetles by hand by flicking them into a bucket of soapy water with a paint brush and drowning them. On small trees this can be a workable control, if not eradication, measure. Beetles attract one another, so reductions in population can help minimize the ongoing infestation.
Pick up and burn all fallen twigs and branches. These will bear the larvae of the twig girdler beetles. Destroying them can disrupt the life cycle of the beetles.
Tent young, small trees with light-, moisture- and air-permeable horticultural fabric when beetle infestations are heavy. Gather and tie the fabric low on the trunk under the canopy. Cover the canopy in the spring after the blooms have been pollinated and dropped to the ground. Remove the covering in the fall or when beetles have moved on for the season.