EXTENSION CORNER with Dustin Adcock: Pecan weevils can devastate a crop of pecans

Published 9:53 am Friday, August 30, 2019

Their ample supply of much-needed shade and the bountiful harvest of pecans in the fall makes the pecan tree a staple of many southern lawns.

That is if you have the space for their mature 75 feet of spread. If you have harvested pecans for any number of years, you are probably familiar with the disappointment of picking up a hollow shell of a pecan. We can thank a little insect known as the pecan weevil for this.

Dustin Adcock

Technically a beetle, the weevil’s life cycle is complete metamorphosis (egg, larva, pupa and adult). The adult emerges from the ground in late summer (August-September) after a heavy rain event.

Then the female, after mating, chews a small hole in the nut and deposits eggs. The eggs will mature into larvae that consumes much of the kernel of the pecan. Then, the larvae will exit the nut and burrow into the ground and pupate for nearly 11 months where they are seldom seen.

The most effective control for pecan weevil is to apply liquid Carbaryl insecticide around the ground, out to the drip line of the tree during mid-August and continuing every week through mid-September. With close observation and spot spraying in subsequent years, less pesticide applications may be necessary.

Keeping the pecans picked up and branches free from the ground will ensure fewer populations of weevils in the future, as well as limit disease potential.

For more information, visit content.ces.ncsu.edu/growing-pecans-in-north-carolina.

Dustin Adcock is the agriculture agent for the Stanly County Center of N.C. Cooperative Extension. Email him at stanly.ces.ncsu.edu or call 704-983-3987.