Lyctus planicollis
Encyclopedia
Lyctus planicollis is a wood-boring beetle in the family Bostrichidae
(formerly in the family Lyctidae, which is now a subfamily of Bostrichidae), commonly known as the southern lyctus beetle or lyctid powderpost beetle. It is a serious pest of hardwoods including ash, hickory, oak, maple and mahogany and can infest many products in the home including hardwood flooring and structural timbers, plywood, furniture, tool handles, picture frames, baskets and ladders. Timber can be infested in one location and then be transported large distances by ship, after which the beetles can emerge and spread the infestation to new areas.
have eleven segments, the end two being broadened giving a club-like effect. The body is elongated and slightly flattened with the pronotum wider than it is long. The elytra are ridged longitudinally, with double rows of small puncture marks between the ridges. The body is covered by a sparse, short yellowish down.
over the course of a week. The eggs are white, cylindrical and about one millimetre long. They are laid deep inside holes in wood, either in the tunnels made by emerging adults or in pores, cracks and crevices. The eggs hatch in one to three weeks depending on the temperature.
The larva
e are cream-coloured and grow to about seven millimetres long as they tunnel deeper into the wood, leaving behind them the powderlike frass
of wood debris that gives them their common name. They feed on the starchy content of the wood as they are unable to digest cellulose. Young larvae chew their way along the grain of sapwood but older larvae may tunnel across the grain. They may come near to the surface but do not break through. When the larvae are ready to pupate, they build pupal chambers close to the surface.
Metamorphosis
takes from twelve days to a month. The adults break out of the pupae
and chew their way to the surface leaving behind circular holes. The little wisps of sawdust that fall from these may be the first sign of an infestation. The adult beetles are nocturnal and may live for up to three months. The whole life cycle takes about a year but can vary from six months to four years. In heated buildings development occurs quickly but in adverse environments, growth is slower and the larvae may hibernate in colder regions. This is the main reason for the variability in the length of the life cycle.
s used in wood paneling, door and window frames, furniture, baskets, hardwood trim and flooring in homes. Infestation usually occurs prior to construction of the article. Varnished, painted or polished surfaces are not normally susceptible to attack but the female beetle may still lay her eggs in empty tunnels created by previous beetle occupants. Subfloors, joists and rafters are usually made of pine or other softwood
and generally escape infestation. Imported tropical hardwoods may be heavily infested because of poor drying and storage practices before shipment.
Bostrichidae
The Bostrichidae are a family of beetles with more than 700 described species. They are commonly called auger beetles, false powderpost beetles or horned powderpost beetles. The head of most auger beetles cannot be seen from above, as it is downwardly directed and hidden by the thorax...
(formerly in the family Lyctidae, which is now a subfamily of Bostrichidae), commonly known as the southern lyctus beetle or lyctid powderpost beetle. It is a serious pest of hardwoods including ash, hickory, oak, maple and mahogany and can infest many products in the home including hardwood flooring and structural timbers, plywood, furniture, tool handles, picture frames, baskets and ladders. Timber can be infested in one location and then be transported large distances by ship, after which the beetles can emerge and spread the infestation to new areas.
Description
The adult beetle ranges from four to six millimetres in length and is a dark brownish-black. The head is prominent and is not covered by the pronotum. The antennaeAntenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
have eleven segments, the end two being broadened giving a club-like effect. The body is elongated and slightly flattened with the pronotum wider than it is long. The elytra are ridged longitudinally, with double rows of small puncture marks between the ridges. The body is covered by a sparse, short yellowish down.
Life cycle
The female beetle mates soon after emerging in the spring and lays up to fifty eggsEgg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
over the course of a week. The eggs are white, cylindrical and about one millimetre long. They are laid deep inside holes in wood, either in the tunnels made by emerging adults or in pores, cracks and crevices. The eggs hatch in one to three weeks depending on the temperature.
The larva
Larva
A larva 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...
e are cream-coloured and grow to about seven millimetres long as they tunnel deeper into the wood, leaving behind them the powderlike frass
Frass
Frass is the fine powdery material phytophagous insects pass as waste after digesting plant parts. It causes plants to excrete chitinase due to high chitin levels, it is a natural bloom stimulant, and has high nutrient levels. Frass is known to have abundant amoeba, beneficial bacteria, and fungi...
of wood debris that gives them their common name. They feed on the starchy content of the wood as they are unable to digest cellulose. Young larvae chew their way along the grain of sapwood but older larvae may tunnel across the grain. They may come near to the surface but do not break through. When the larvae are ready to pupate, they build pupal chambers close to the surface.
Metamorphosis
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation...
takes from twelve days to a month. The adults break out of the pupae
Pupa
A pupa is the life stage of some insects undergoing transformation. The pupal stage is found only in holometabolous insects, those that undergo a complete metamorphosis, going through four life stages; embryo, larva, pupa and imago...
and chew their way to the surface leaving behind circular holes. The little wisps of sawdust that fall from these may be the first sign of an infestation. The adult beetles are nocturnal and may live for up to three months. The whole life cycle takes about a year but can vary from six months to four years. In heated buildings development occurs quickly but in adverse environments, growth is slower and the larvae may hibernate in colder regions. This is the main reason for the variability in the length of the life cycle.
Damage
The larval stage is responsible for nearly all the damage done by the beetle. They feed on many of the various hardwoodHardwood
Hardwood is wood from angiosperm trees . It may also be used for those trees themselves: these are usually broad-leaved; in temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen.Hardwood contrasts with softwood...
s used in wood paneling, door and window frames, furniture, baskets, hardwood trim and flooring in homes. Infestation usually occurs prior to construction of the article. Varnished, painted or polished surfaces are not normally susceptible to attack but the female beetle may still lay her eggs in empty tunnels created by previous beetle occupants. Subfloors, joists and rafters are usually made of pine or other softwood
Softwood
The term softwood is used to describe wood from trees that are known as gymnosperms.Conifers are an example. It may also be used to describe trees, which tend to be evergreen, notable exceptions being bald cypress and the larches....
and generally escape infestation. Imported tropical hardwoods may be heavily infested because of poor drying and storage practices before shipment.