Twig Drop of Trees
There are two main causes of twig drop among trees in a landscape. Homeowners will often notice small twigs that have fallen on a lawn, patio, or driveway. Squirrels are often the culprit in the spring. The other cause of twig drop may be from an insect known as a twig girdler.
The twig girdling insect is a long-horned beetle with a grayish-brown body that is stout and cylindrical. The larva is also cylindrical with a small head and shiny body. Girdled twigs often remain on the tree until sufficient wind dislodges them. Large infestations can result in a high percentage of twigs being girdled. Though this may reduce the vigor and overall appearance of the tree, the overall effect on the tree’s health is not severe. Twigs are unsightly however, and do not fall all at once, making clean-up difficult.
Chemical control of twig girdlers is impractical. Fallen twigs can be gathered and disposed of either in the fall or in the spring. This will destroy the twig girdler larvae, implanted inside twigs. Larvae often die anyway, due to excessive drying of fallen twigs or too many larvae per twig.
It is relatively easy to tell the difference between twig girdler damage versus squirrel damage. Girdler damage looks like the branch has been fed on by a beaver; very smooth and cone shaped. Squirrel damage is more tattered and cut at an angle. Girdling damage from insects is usually seen in the late summer or early fall. Squirrel damage is often seen in the spring, but can occur anytime.
The bottom line for squirrel and twig girdler damage is to do nothing. In most cases, squirrels and twig girdlers do not pose serious harm to your trees. If you have an excessive squirrel population, call your local county extension office for proper control procedures.
Related Information: Squirrels, Urban Wildlife Damage Control Twig Girdlers; www.oznet.ksu.edu