Powder post beetles can infest any item made of wood, but there are multiple ways to eliminate them and prevent their return. Chemicals applied to infested wood often will do the trick, but in some instances, it might be necessary to use poison gas after tenting an infested structure.
Probably the best way to deal with powder post beetles is to prevent them from ever infesting wood in the first place. Carefully selecting lumber that has been kiln-dried and then varnishing the wood will help keep powder post beetles from becoming a problem.
Eliminating Powder Post Beetles
Several chemicals can be used, but they do not penetrate sealed wood. A more extreme—and expensive—measure is to tent the house and use poison gas to eradicate the beetles.
Ask a pest control professional for advice about your specific situation. In some cases, you'll find that having a few powder post beetles in your home is nothing to be overly concerned about. A pest control professional might tell you to simply watch for further development.
If you want to stay away from chemicals or handle the problem yourself, Organic Daily Post recommends using cedar oil. It is not harmful to insects like bees and butterflies that play an important part in the ecosystem, but it can be a safe and natural repellant for pests, including powder post beetles.
Another method Organic Daily Post recommends is putting the pests through extreme temperature changes. This generally is only effective with smaller items like chairs and tables that can be moved from one environment to another. Place the infected wood in temperatures no warmer than 10 degrees Fahrenheit for three days, then move it back to a warmer room, then repeat the process. Powder post beetles are incapable of surviving the extreme shifts in temperature.
If you're buying a home, look closely at wood beams and other structural components for beetle exit holes and sawdust. If you find traces of a beetle infestation, have a pest professional inspect the home.
If the infestation appears to be severe, consider having an engineer or general contractor inspect the structural integrity of the home.
Rough-cut lumber should be kiln-dried before use, according to pestkilled.com. It speeds up the process of drying green lumber by placing it in a heat- and moisture-controlled kiln that circulates dry air at temperatures ranging from 125 to 140 degrees Fahrenheit. Doing this also kills powder post beetles in all of their stages of life. It's important to note, though, that even kiln-dried lumber stored in an exposed environment can become infested. The lumber can regain moisture if left outside or in a barn, and powder post beetles or other pests also will have easy access.
For projects like tables, chairs, or desks, sanding and varnishing the lumber keeps out powder post beetles by ridding the wood of the tiny crevices necessary for the pests to lay their eggs. Painting the wood can serve as a similar deterrent.
Borate-based pesticides also can prevent infestations, but it's important to spray the wood before finishing it. Varnishes associated with the finishing process prevent the wood from absorbing the pesticide.
Other ways to prevent a powder post beetle infestation are as follows:
- If your house sits on a crawl space or has a dirt basement, cover the earth with plastic to reduce moisture. Watch the surface of the plastic for sawdust falling from floor joists above.
- Inspect the floor or moldings beneath interior wood walls. Little piles of sawdust indicate beetles have been in the wood, but they are not necessarily a sign of active infestation.
- Schedule yearly inspections with a qualified inspector.
Most powder post beetles like wood with a high moisture content, but some beetles prefer to live in dry wood. Adult beetles are dark brown to black and only 1/8-inch to 1/4-inch long. Second only to termites as a threat to wood structures, powder post beetles can be found in any region or climate. The transport of lumber around the country and internationally allows the beetles to find their way to all parts of the globe.
Powder post beetles may infest wood at any stage in the manufacturing process or on a construction site. Unsealed wood can harbor beetle larvae, so adults might not emerge until long after your home has been constructed. It even could take several years, depending on the species and individual conditions. The heat from kiln-drying kills all stages of powder post beetles, and although dried wood is not as attractive to them, the process is not an absolute cure for reinfestation.
Adult beetles lay eggs in the crevices of untreated wood. When larvae hatch, they start tunneling. Sometimes, you can see the outline of tunnels near the wood's surface, following the soft areas of the grain, but in many cases, you can't see any evidence at all that larvae are present.
As the larvae bore, the tunnels behind them become packed with sawdust. They stop near the surface of the wood, where they mature.
Adults break through the surface, leaving tiny round holes where they emerge. Sawdust spills from the hole and can continue to spill out for some time even though an infestation is over.
Both hard woods and soft woods are susceptible to powder post beetles, according to researchers at Michigan State University, because different species of the pest have different preferences. Some species have no preference and will infest either hard wood or soft wood.