Part 1

Produced by Tom Cosmas compiled from images made available by The Internet Archive.

Powder-post Beetles in Buildings

What to Do About Them

by R. A. St. George and T. McIntyre

POWDER-POST BEETLES

in Buildings

what to do about them

Leaflet No. 358

U.S. DEPARTMENT OF AGRICULTURE

Powder-Post Beetles in Buildings

WHAT TO DO ABOUT THEM

Powder-post beetles cause extensive damage to wood in the structure of buildings and to wood products used in homes.

The larvae, or grubs, feed on the starch or the cellulose in wood. As they feed, they bore irregular tunnels through the wood. Borings left in the tunnels have the consistency of powder.

Powder-post beetles can be controlled by applying an insecticide to the infested wood. How it is applied depends on the kind of beetle to be controlled and on the extent and location of the infestation. In some circumstances a spray will suffice; in others, fumigation is necessary.

+--------------------------------------------------------------+ | | | COMMON AND SCIENTIFIC NAMES OF INSECTS DISCUSSED | | | | Southern lyctus beetle Lyctus planicollis | | Common furniture beetle Anobium punctatum | | Death-watch beetle Xestobium rufovillosum | | Old house borer Hylotrupes bajulus | | Red-shouldered shothole borer Xylobiops basilaris | | Black-horned pine borer Callidium antennatum | | Bamboo powder-post beetle Dinoderus minutus | | Bamboo borer Chlorophorus annularis | | | +--------------------------------------------------------------+

KINDS

Powder-post beetles are divided into five groups--lyctus beetles, anobiid beetles, bostrichid beetles, cerambycid beetles, and cossonid weevils.

Lyctus beetles are reddish to blackish, about 1/4 inch long, and slightly flattened. One common species is known as the southern lyctus beetle.

Anobiid beetles are similar to lyctus beetles in color and size, but are cylindrical. The common furniture beetle and the death-watch beetle belong in this group.

Bostrichid beetles are reddish, brown, or black; they are 1/8 to 3/4 inch long, and cylindrical.

The heads of anobiids and bostrichids are directed downward and are covered by a "hood."

The cerambycids, also known as roundheaded or long-horned beetles, are blue, black, or pale yellow to reddish brown, and often bear distinctive markings on the head or the wing covers. They are 1/2 to 1 inch long, and vary in shape. The old house borer belongs in this group. It is black, and has grayish markings on the wing covers. It is about 3/4 inch long.

Cossonid weevils are reddish brown or black, 1/8 to 1/5 inch long, and oval to cylindrical. Their heads are drawn out to form a short, broad beak. Cossonids are the only weevils that infest wood; other weevils infest grain or growing crops.

LIFE CYCLE

The adult females lay eggs on or in wood. The eggs hatch into larvae, which develop as they tunnel the wood. The tunneling continues throughout the larval stage, which lasts for months or years, depending on the kind of beetle.

The full-grown larvae transform to pupae, which become adult beetles.

The adults of many kinds of powder-post beetles bore circular holes to the surface of the wood and emerge; others make oval holes. Some emerge in early spring; others, including the old house borer, emerge in early summer. Mating and egg laying follow.

The life cycle of lyctus beetles varies from 3 months to 1 year, depending on the species and on regional differences in temperature, moisture, and availability of wood of high food value.