Facts About Longhorn Beetles

Longhorn beetles are attracted to sick, dying, freshly cut, or recently killed trees where they lay eggs on the bark of the tree. The larvae emerge from the eggs and burrow into the tree and spend one to three years, sometimes more, tunneling through the wood. When silviculturists (lumber farmers) harvest wood for buildings or furniture, they put the logs through processes such as autoclaves or steam treatments to get rid of beetles and insects of all types. However, sometimes longhorn beetles evade the treatment and survive through the final processed lumber. When this happens, they can be in the wood that makes up your home or furniture.

Longhorned beetles spend the majority of their time as larvae inside the wood. As adults, they emerge and can be a nuisance, but they cannot bite or sting. And rarely will they reinfest a piece of wood already dried and used for carpentry (it’s very, very rare that this happens). This is because they do not infest cured lumber (such as in the house structure or in furniture) nor dried firewood. They do love dying, freshly cut, or recently killed trees. Their tunnels may be just under the bark or in the heartwood, are usually about the size of a lead pencil, and are packed with coarse sawdust. The larvae are wormlike white to yellowish with a brown head and deeply wrinkled bodies. Exit holes and piles of sawdust mark where the adult beetles have emerged from the infested wood. They weaken the wood and trees basically from the inside out. Lumber with lots of tunneling can be structurally compromised as well. You might even see meandering tunnels in a piece of wood that was previously infested. It’s hard to tell. That’s why you need an expert to come and assess if you have an active infestation or just evidence of beetles past.

The best way to prevent longhorn beetles coming from firewood is to leave the firewood outside until it going to be burned, bringing (at most) a few days’ supply into the house at one time. Beetles that do emerge from firewood inside the house need only be picked up and thrown away. If you suspect that lumber used at your house might have longhorn beetles, Western Fumigation can come and offer an inspection to help you determine if there is an active infestation. And if so, fumigation can certainly take care of these pests.