How To Deal With House Beetles
While there are many types of insects that find a way into one’s home, house beetles constitute the largest group of their kind. And while many are merely nuisance pests, others can cause substantial damage if not discovered and stopped in time.
We start with the Longhorned beetle. Ranging in size from ½”-1.5,” they grow and develop inside trees or logs. Since they will never invade a home on their own, the only way this can occur is if larva-infested firewood is carried inside. These house beetles are harmless and should not be harmed or destroyed, but taken outside if discovered in the home.
The foreign grain beetle is red-brown and 2 mm long. Only attracted to newer structures, they feed on fruit, cereals, grains and spices. For this reason, it is a good idea to store all their favorite foods inside closed containers. Like the longhorned beetle, they pose no threat to structures or furniture.
Ground beetles are dark-colored and about 1” long. More likely to invade the home in the fall when temperatures drop, they are more interested in eating insects than anything else, and will not survive for long indoors. They are harmless, and more of a nuisance than anything else. If found, they should be returned to the outdoors.
Weevils of the house-invading variety belong to one of four species: longhorned, strawberry root, black vine and Asiatic oak. They tend to enter homes during the summer and fall months, when they aren’t busy chewing on ornamental plants. They do no harm and should be removed, not destroyed.
Due to the fact that they seek out and devour aphids, Multicolored Asian Lady beetles are one of the more beneficial insects of their class. Of yellowish color and about ¼” long, they enter homes through door and window cracks, and at times, when the sun is out, they will be seen flying from one spot to another. Because they are so beneficial as pest controllers, every effort should be made to seal voids with caulking so that they cannot find their way inside the home.
Second only to termites, the Lyctid and other “powderpost” beetles are the most destructive wood borers in existence. A sure sign these house beetles are at work is the telltale pile of wood powder at the base of their boreholes. At ¼” long, Lyctids live in oak and other hardwoods, and begin boring their way through once they reach the larval stage, pushing the wood dust out as they continue moving toward the wood’s surface. Due to the fact that the female lays between 20-50 eggs at a time, it won’t be long before one’s home is full of beetles.
Though the majority of the 200 types of Anobiid (or Deathwatch) beetles eat grain, the powderpost variety infests softwoods and hardwoods, including walnut furniture. Like the Lyctid beetle, the Anobiid larvae bore through wood, but once they reach adulthood, continue boring, as evidenced by the 1/8” holes they leave behind.
Bostrichid Powderpost beetles do less harm than other wood-borers in that they only attack hardwoods.
At 1” in length, the Cerambycid (Old House Borer) beetles are the probably the largest of the destructive wood-borers. Attracted to softwoods, both the larvae and the adults bore holes.
Having read the above list of destructive insects, one’s thoughts immediately turn to insecticides- but this may not be the best or only solution to the problem. One of the reasons that homes are targeted by destructive beetles has to do with high moisture content. As such, installation of moisture barriers, as well as central air conditioning and heating will go along way toward eliminating beetle infestations.
Other solutions range from spot treatments with insecticides to replacement of infested wood sections, and wood sealants.
As for insecticides, brands such as Dursban may be available, but you are probably better off seeking the help of a professional, due to the potential complexity of the problem.
Fumigation is another option, but again, it must be carried out by professionals, and may have to be repeated several times throughout a one-year period to completely kill all the nested insects.