Borer Beetle
Facts about the Borer Beetle
Borer beetle infestation is a dreaded event for anyone who has trees prized for their beauty, fruit or lumber. Shade trees, fruit trees, and conifers are frequent victims of this destructive insect, so knowing the signs and habits of it can help you to save your trees.
Through their habit of tunneling into trees, the borer beetle weakens the tree, damages its wood and lowers the tree’s commercial value for lumber and veneer. In fact, the harm created by these beetles is usually so drastic that the tree will either die on its own or face the need to be destroyed before infestation reaches other trees as well.
It is the immature larvae of the borer beetle that creates the injury to the tree. Eggs by the adult beetle are laid, usually on the bark of a tree or within the bark’s rough crevices. When the larvae emerge, they embark on a destructive path by tunneling under the bark or deep within the tree trunk itself. The tunnels are called galleries which widen as the larvae grows, chewing a wider swathe as it travels. Their work is not limited to the trunk; branches, roots, shoots may be affected depending on the type of beetle and the type of tree.
Many times, a particular tree is invaded by the borer beetle because the tree is already in a weakened condition; either from previous beetle attack or some other source. The type of beetle in these circumstances is called a secondary pest. Healthy trees and woody plants are the target of other types of beetle called a primary pest.
Unless trees are routinely scrutinized by professionals, attacks of the borer beetle may go unnoticed until the trees begin to show stress. This can occur through defoliation, oozing sap and the tell-tale signs of the minute holes bored by the larvae. A few varieties of the beetle excrete enough frass as to emerge from the tree as semi-solid “straws”; poking out at all angles in cases of extreme infestation.
Preventative measures include fostering healthy trees. Choosing only trees that match the environment where they will receive the nutrients needed through feedings and watering are the best defense against the borer beetle in most cases. Avoid pruning during productive periods, which result in open wounds; a favorite condition for the beetle. Where invasion has already begun, chemical warfare may be required; an expensive and repeated process. Often, elimination of the affected tree is the best option to avoid further infestation.
Protection can be a simple matter of maintaining a healthy status of the tree. Whenever possible, it is a healthier and easier matter to prevent the borer beetle than to eliminate its presence from the trees you prize.