Fig-tree borer larva Phryneta spinator 2145

Powderpost beetles are a group of seventy species of

woodboring beetle The term woodboring beetle encompasses many species and families of beetles whose larval or adult forms eat and destroy wood (i.e., are xylophagous). In the woodworking industry, larval stages of some are sometimes referred to as woodworms. The ...

s classified in the

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs ...

subfamily Lyctinae. These beetles, along with

spider beetle Spider beetles make up the subfamily Ptininae, in the family Ptinidae. There are approximately 70 genera and 600 species in the subfamily, with about 12 genera and 70 species in North America north of Mexico. Spider beetles have round bodies wi ...

death watch beetle The deathwatch beetle (''Xestobium rufovillosum'') is a species of woodboring beetle that sometimes infests the structural timbers of old buildings. The adult beetle is brown and measures on average long. Eggs are laid in dark crevices in ol ...

common furniture beetle The common furniture beetle or common house borer (''Anobium punctatum'') is a woodboring beetle originally from Europe but now distributed worldwide. In the larval stage it bores in wood and feeds upon it. Adult ''Anobium punctatum'' measure i ...

skin beetles Dermestidae are a family of Coleoptera that are commonly referred to as skin beetles. Other common names include larder beetle, hide or leather beetles, carpet beetles, and khapra beetles. There are over 1,100 species described. Dermestids have ...

, and others, make up the superfamily

Bostrichoidea Bostrichoidea is a superfamily of beetles. It is the type superfamily of the infraorder Bostrichiformia. Description The Bostrichoidea are united by the following features: modified cryptonephridism, the structure of the aedeagus in males, a ...

. While most woodborers have a large

prothorax The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on e ...

, powderpost beetles do not, making their heads more visible. In addition to this, their antennae have two-jointed clubs. They are considered

pests PESTS was an anonymous American activist group formed in 1986 to critique racism, tokenism, and exclusion in the art world. PESTS produced newsletters, posters, and other print material highlighting examples of discrimination in gallery represent ...

and attack

deciduous trees In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, af ...

, over time reducing the wood to a powdery dust. The damage caused by

longhorn beetles The longhorn beetles (Cerambycidae), also known as long-horned or longicorns, are a large family of beetles, with over 35,000 species described. Most species are characterized by extremely long antennae, which are often as long as or longer tha ...

(family Cerambycidae) is often confused with that of powderpost beetles, but the two groups are unrelated. The

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. Th ...

e of the Cerambycidae are white, straight and generally flat-headed, whereas those of the Bostrichidae are white and C-shaped.

Name

The term "powderpost" comes from the fact that the larvae of these beetles feed on

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of ligni ...

and, given enough time, can reduce it to a mass of fine powder. Because of this behavior, they are considered pests. These beetles can survive in colder climates.

Life cycle

Powderpost beetle larvae spend months or years inside

while developing, feeding mainly on the starch content. Their presence is only apparent when they emerge as adults, leaving behind pinhole-sized openings, often called "shot holes". They may also leave piles of powdery

frass Frass refers loosely to the more or less solid excreta of insects, and to certain other related matter. Definition and etymology ''Frass'' is an informal term and accordingly it is variously used and variously defined. It is derived from the G ...

below. Shot holes normally range in diameter from to , depending on the species of beetle. If wood conditions are right, female beetles may lay their eggs and re-infest the wood, continuing the cycle for generations.

Target materials

Powderpost beetles feed on

, including certain

hardwood Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes fro ...

s or

softwood Scots Pine, a typical and well-known softwood Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees. The main differences between hardwoods and softwoods is that the s ...

s depending on the species. Some hardwoods are naturally immune if they have low starch content or if their pore diameters are too small for the female beetle's

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typica ...

to lay her eggs in.

Wood preservatives Wood easily degrades without sufficient preservation. Apart from structural wood preservation measures, there are a number of different chemical preservatives and processes (also known as "timber treatment", "lumber treatment" or "pressure treat ...

can be used to prevent beetle infestation. Common treatments may use

borate A borate is any of several boron oxyanions, negative ions consisting of boron and oxygen, such as orthoborate , metaborate , or tetraborate ; or any salt with such anions, such as sodium metaborate, and disodium tetraborate . The name a ...

, and frequently structural

fumigation Fumigation is a method of pest control or the removal of harmful micro-organisms by completely filling an area with gaseous pesticides—or fumigants—to suffocate or poison the pests within. It is used to control pests in buildings (s ...

. Items that can be infested by powderpost beetles include wooden tools or tool handles, frames, furniture, gun stocks, books, toys, bamboo, flooring, and structural timbers.

References

Bibliography

External links

* *
Lyctinae at Fauna Europaea

Powderpost Beetle Fact Sheet
from the National Pest Management Association with information on habits, habitat and prevention

at the

National Park Service The National Park Service (NPS) is an List of federal agencies in the United States, agency of the Federal government of the United States, United States federal government within the United States Department of the Interior, U.S. Department of ...

.
Powderpost beetles – The other, other wood destroying insects
from Michigan State University Extension.

the effect of beetles on wooden structures. {{Taxonbar, from=Q2638541 Bostrichidae Building defects Household pest insects Woodboring beetles