Part 2

The life cycle of anobiid beetles is sometimes completed in about 1 year and sometimes in 2 years.

Most of the bostrichids and cerambycids complete the cycle in about 1 year, but a few of the latter require several years. The old house borer, a cerambycid, requires 5 to 7 years in the North, and less time in the South. In all but a few months of its life cycle, it is in the larval stage. Larvae 3 or 4 years old are often found in the woodwork of buildings only 1 or 2 years old--evidence that stored lumber is a source of infestation.

Cossonid weevils complete the cycle in about 1 year.

EGG LAYING

The females lay eggs on or in wood that satisfies their egg-laying requirements and the food requirements of the larvae. These requirements differ among the species. Hence different kinds of wood are infested by different species of beetles.

Lyctus beetles infest hardwoods. Cossonid weevils infest softwoods. Some anobiids, bostrichids, and cerambycids infest hardwoods, and some infest softwoods.

For some species bark is an egg-laying requirement; for others it is not.

Some anobiids infest moist wood containing decay organisms, which appear to aid development of the larvae.

Cover: Adult of an anobiid beetle, Xyletinus peltatus, and pine sill damaged by larvae of this beetle.

The porosity of the wood, the moisture content, the starch or cellulose content--these also relate to egg laying.

The adults of some species remain on the wood from which they emerge, and reinfest it. Others crawl or fly to similar wood and attack it.

A beetle may lay only a few eggs or as many as 60 or 70; the number depends on the species of beetle and on the condition of the wood.

=Infestations in Hardwoods=

Seasoned hardwoods.--Beetles that infest seasoned hardwoods lay eggs on or in the wood from which they emerge. Hence the same wood may be infested repeatedly. These beetles do not require bark for egg laying.

Lyctus beetles lay eggs in exposed pores in the sapwood of oak, ash, hickory, walnut, pecan, gum, persimmon, maple, cherry, and a few other hardwood species. The larvae are found in hardwood flooring, furniture, picture frames, and trim.

Anobiid and cerambycid beetles lay eggs in crevices on the surface of the wood; cerambycids also lay eggs in emergence holes.

Bostrichid beetles that bore into seasoned hardwoods often bore chambers at the sides of their tunnels and lay eggs in them.

Unseasoned hardwoods.--Bostrichids that infest green and seasoning hardwoods lay eggs in pores leading from the entrance tunnels. The red-shouldered shothole borer is one of these. Bostrichids frequently attack bark-covered wood. They usually do not reinfest the wood from which they emerge.

=Infestations in Softwoods=

Seasoned softwoods.--Some kinds of beetles infest seasoned softwood lumber used in the structure of buildings.

Certain of the bostrichids require bark for egg laying. They infest lumber that has bark on the edges. Such lumber is often used in framing, subflooring, and roofing. The females lay eggs in the bark. The larvae of some species complete their development in it; others go to the adjacent wood to do so. The adult females may reinfest the wood from which they emerge.

Other beetles that infest seasoned softwoods do not require bark for egg laying. Among them are the old house borer and the cossonid weevils. The females lay eggs in crevices in the wood. They may infest the same wood repeatedly.

The old house borer infests framing and subflooring. It is found in old and new construction and in stored lumber. Cossonid weevils are found in pine flooring, baseboards, wall stops, and roof trusses.

Unseasoned softwoods.--The beetles that infest green and seasoning softwoods include several cerambycids--for example, the black-horned pine borer--and a few bostrichids. Most of these beetles require bark for egg laying. The adult females usually do not reinfest the wood from which they emerge; they seek other unseasoned wood and lay eggs in the bark.

=Infestations in Bamboo=

Certain species of bostrichid, cerambycid, and lyctus beetles infest bamboo products such as furniture. Venetian blinds, draw drapes, baskets, fans, and fishing poles.

Plant-quarantine inspectors at United States ports of entry often intercept the beetles in bamboo products imported from the Far East. Among the beetles intercepted are the bamboo powder-post beetle, a bostrichid, and the bamboo borer, a cerambycid. These beetles and the lyctus beetles may reinfest the material from which they emerge.

DAMAGE