Unusual Pests of New Homes

Editor’s Note: This article was reprinted with permission from Pinto & Associates.

Logic says that a new home is the least likely to be infested with pests. But insects and other pests do not understand logic! A few months to a year after moving into a new home the residents may be faced with an outbreak of "bugs" of one sort or another. The cause is often moisture, which not only leads to fungus and rot, but also to sudden outbreaks of unusual pests.

In newly built homes and other buildings, these pests feed on the fungus growing on the surface of wet wood, drywall, plaster, and other building materials. The most common new construction pests in the fungus-feeding category are the following:

• Foreign Grain Beetle: The number one unusual pest in new construction, this beetle does not actually feed on grain but on fungus growing on damp grain, or on any other surface such as wood or other building materials in a home. In late summer and early fall, the foreign grain beetles move out of hidden areas and are attracted to light.

• Psocids: Commonly called booklice, although they are not parasites, these tiny fungus-eating, soft bodied, and usually wingless insects are common pests of homes and commercial buildings with moisture problems. In new homes with high moisture levels, psocid populations can explode at any time during warm weather in crawlspaces, basements, and on the back side of damp plaster and Sheetrock walls and then spread into living areas. Eggs and small nymphs can survive cold temperatures, also causing a population outbreak a few weeks after warm weather starts in the spring. 

• Plaster or Mold Beetles. Several species of these tiny beetles can become pests in new construction. They feed on mold spores, and in new homes they feed especially on mold spores located in wall voids. Similar beetles which may become pests in new construction are the silken fungus beetle and the minute brown scavenger beetle.

For all fungus-feeding pests, as the structure dries out, the fungus will dry out, and the pests will die out. Unfortunately, this can take a long time, although you can speed up the process with fans and dehumidifiers, by running the furnace, installing vents, and by opening up voids to let them dry. Naturally, any leaks, condensation issues, or wet basements will have to be corrected beforehand.

Pests are sometimes built into newly constructed buildings. These can include the following: 

• Rats and Mice. As a building is constructed, walls and other spaces are left open for months, both inside the building and to the outside. Rats and mice have an open invitation. Stored construction materials provide harborage, and construction workers leave hamburger scraps, fries, chicken bones, and other high energy foods, fostering a build-up of rodents. As the building is completed, some of the rodents become trapped inside.

• Wood Boring Beetles. Homes and other wood-based structures may use lumber infested with certain wood boring beetles. After a time, these beetles begin emerging or otherwise making their presence known. Examples include long-horned beetles, flatheaded and metallic wood borers, wood wasps, and powderpost beetles. Most are simply aggravating, but a few can reinfest and cause structural damage and so must be controlled in some way.

The authors are well-known industry consultants and co-owners of Pinto & Associates.

Source: Best Practices for Wildlife Control Operators NYSDEC/Cornell CES.