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Longhorned Beetles

There are several different types of long-horned beetles, including the Asian Long-Horned Beetle. These beetles are all very harmful to a tree and often cause death, if not treated properly as soon as possible.

Long-horned beetles, like all types of burrowing insects, are extremely destructive because, as the beetle larvae burrow deep within a tree to feed, they disrupt the tree’s vascular system. Continued feeding causes structural defects and eventually kills the life-sustaining cambial layer by girdling (strangling the tree). Mature beetles then burrow out of the tree, leaving holes the diameter of ball-point pens. Active Long-horned Beetle infestations, if left untreated, can quickly kill otherwise healthy adult trees.

Mature beetles emerge from trees in late May and through October, peaking in July. Tree infestations can be detected by looking for tell-tale exit holes 3/8 to ¾ inches in diameter (1.5-2 cm). They are often in the larger branches of the crowns of infested trees. Sometimes sap can be seen oozing from the exit holes, with coarse sawdust or ‘frass’ in evidence on the ground or lower branches.

Recommended Steps to Help Control Long-horned Beetles

If a tree has been attacked by Long-horned Beetles, immediately apply the Multi-Insect Killer Tree Injection Kit directly into the tree’s vascular system. To help provide protection throughout the growing season to trees that are located in an area of Long-horned Beetle outbreaks, apply Once-A-Year Insecticidal Drench w/Merit early in the spring.

Boring insects are less likely to attack strong, healthy trees, so a proper fertilizing and watering program using the TreeHelp Annual Care Kit is recommended, to ensure trees are strong and healthy and to help trees that have been attacked repair damage done by the boring insect.