The culprit that cuts the limbs off pecan trees is a pesky insect known as the twig girdler. These little pests can also be found on other trees such as elm, hickory, and persimmon. They are not picky eaters and will even attack oaks, honey locust, hackberry, poplar, dogwood, sourwood, and various fruit trees.
The lifecycle of a twig girdler begins when the adult beetles emerge from late August to early October. These beetles are about half an inch long and have long antennae. They are typically brownish-gray or black in color. Once they emerge, they mate and the females begin their destructive mission.
The female twig girdler uses her mandibles to chew around the circumference of small branches or twigs on the tree. This creates a distinct “girdle” or ring around the branch. The girdling weakens the branch and ultimately causes it to die and fall off. The female then lays her eggs in the dead branch, typically in the area below the girdle.
The larvae of the twig girdler hatch from the eggs and begin to feed on the dead wood. They tunnel their way through the branch, creating small tunnels and galleries as they go. This feeding activity can weaken the branch even further and make it more susceptible to breaking.
Once the larvae have completed their development, they pupate inside the branch. They will remain in this stage throughout the winter and emerge as adults the following year, continuing the cycle once again.
Dealing with twig girdlers can be frustrating for gardeners and tree owners. One way to control these pests is by physically removing and destroying any affected branches. This can help prevent the beetles from spreading further and laying their eggs in healthy branches.
Another method is to use insecticides specifically targeted towards twig girdlers. Consult with a professional arborist or garden center to determine the best product and application method for your specific situation.
In my personal experience, I have had to deal with twig girdlers on my pecan trees. It was disheartening to see the branches being cut off and the overall health of the tree being compromised. I found that a combination of physically removing affected branches and using insecticides helped to mitigate the damage caused by these pests. It required diligence and regular monitoring of the trees, but eventually, the infestation was brought under control.
The twig girdler is a common pest that cuts the limbs off pecan trees and other susceptible tree species. Understanding their lifecycle and implementing appropriate control measures can help protect your trees from their destructive behavior.
