New Housing Problems

Q. We have a new customer that is experiencing "bug" problems. These small, reddish-brown insects are found mostly in the bathroom, but have also been found in the foyer area. The house is fairly new; it’s been less then a year since they first moved in. Can you identify these insects and give us some advice? (C.B., Chicago)

A. The "bugs" are foreign grain beetles. But do not let this insect’s common name fool you. This beetle is not always found in grain. They are small, reddish in color and very similar to the red (and easily confused) flour beetle. But they actually are more closely related to the sawtooth grain beetle.

Foreign grain beetles are fungus feeders. That is, when found in grain, they are usually feeding on the damaged or moldy grain. They also feed on molds and mildews in a variety of situations. The problem here is that in new homes, the beetles are feeding in the walls on mildew. This probably came about when building materials got wet during the building of the structure. As the house goes through its first heating and air-conditioning adjustment, the walls will "dry out" and the habitat these insects need to survive will disappear. The beetles will also disappear soon.

For immediate relief, you may want to check the wall for high moisture and humidity in the area where the beetles are found. If higher moistures are found, injecting a dust into the wall through the switch plates or under the baseboards can alleviate the immediate problem.

Q. One of our newest customers has an insect problem that we have identified as psocids. She is quite upset because she has read where these are commonly called paper mites or paper lice and she is concerned about her painting and book collections. Can you help us with identification? Also, how can we alleviate her fears? (K.G., Richmond, Va.)

A. Certainly you have identified the insect correctly. (The customer had even had the insect’s identification confirmed by the university extension office.)

First, the home is new and most probably during the construction, building materials got wet and it is taking a while for these to dry out. Generally it takes more than a year for materials like insulation and wallboard to dry completely and the humidity and moisture to leave the structure. The psocid (as PCOs know) needs a certain level of humidity to survive. Her concerns about damage are not to be brushed off because the evidence indicates there was a large population and in the right situation, they can damage books and paper products. However, after discussing the various requirements these insects need to survive she seems to be pretty well convinced that they will not do damage to her collections. The population does seem to be dissipating, with fewer insects being caught in sticky traps that were placed.

Your efforts to discuss this with her are to be commended. Extreme patience is needed in cases like this, which border on delusional parasitosis (insect phobia). She sees these things virtually everywhere (even though during our inspection we could only find a few dead ones). I believe the dusting performed in some areas where high numbers were being observed also assisted in reducing populations.

Q. A new home, less then four months old, has experienced emergence of woodborers. The homeowner is very concerned about an active infestation in the structure and a recurring beetle infestation. What are the beetles and what can we expect? (B.H., Charlotte, N.C.)

A. Since the homeowner actually captured two of the beetles that were emerging from the wood, it was easy to see this was an interesting case. The two captured beetles were buprestid beetles, commonly called the flathead borers, because of the appearance of the larvae. This particular beetle is found on the East Coast but more commonly appears in wood from the West Coast. This is the case here — the wood with the damage (and where the beetles emerged from) is from western Canada. (We found this out by getting information from the homebuilder.)

The third beetle that was found in the structure was originally identified as an old house borer (OHB). Now this one can be a problem, but the emergence being so soon after construction really does not sound right. I inspected all the exposed wood in the structure and could not find an emergence hole or evidence of this beetle. Interestingly, the other wood in the structure is southern pine, a wood commonly infested by old house borers. Also complicating this is that the beetle was no longer available for identification. However, I was shown a picture taken by the homeowner and from that I determined it was not an OHB. Therefore, I am not concerned that either of these beetles will cause more problems in the structure.

The problem is that the supposed old house borers and some of the damage existing in the wood were both identified by two other people as old house borer damage. This caused undue concern.

This case was interesting because the homeowner also accessed the Internet for information. When I showed up, they already knew that the beetles were non-reinfesting and that the OHB was actually another common wood borer found in southeastern forests and was an incidental/accidental fly in.