Frequently Asked Questions About Insects - Department of Entomology at Texas A&M University

Frequently Asked Questions

Topic:	Beetles, powderpost
Question:	I live in a 2-year old house in the state of Washington. We had oak floors installed in the main floor of the house. About a year after the house was completed, we found an area of the floor with 15 perfectly round holes. They ranged in size from 1/32 of an inch to 1/8 of an inch in diameter. We captured what appeared to be a black, skinny beetle. We sprayed the holes, but now, 6 months later, we have new holes in various locations of the floor. The pest control serviceman said he thought the bugs came in with the wood - the oak was not kiln dried properly. Our treatment 6 months prior didn't kill the eggs in the wood from when it was harvested. He suggested we replace the floor, his rationale being that we can continue to kill the bugs as they hatch, but not the eggs in the flooring. He also said the eggs can take up to three years before hatching. Any advice you can give us is appreciated.
Answer:	It sounds like powder post beetle, but you may want to confirm the identity with a local expert. There are three main control measures. 1. Tarp and fumigate the home. It is expensive, but kills everything, even in the wood, if done right. 2. Replace the wood. This removes the damage and clean wood can be used to replace it. There is some small risk that beetles have moved to other parts of the structure. 3. Surface treat the wood. The life cycle is slow and there may be beetles emerging for 5 years or more. Surface treatment will not kill the beetle larvae inside the wood, but inhibits egg laying in the wood again. Sawdust is pushed out of the holes indicating an active infestation. It is always a judgement call about which method to select.
Related Link:	http://citybugs.tamu.edu/FastSheets/Ent-1022.html
Related Link:	http://ext.wsu.edu/
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Response by:	John A. Jackman, Ph.D.
Title:	Professor and Extension Specialist
** Most of the Related Links above also contain images.

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