Anobiid beetles in timber in Queensland
B.C. Peters, J. King and F.R. Wylie
There are approximately 1100 species of anobiid beetles (Family Anobiidae) world-wide, but only about 200 of these occur in Australia. In Queensland, four species of anobiid may be found in or around buildings. The pine bark anobiid Ernobius mollis (Linnaeus) and the cigarette beetle Lasioderma serricorne (Fabricius) are of minor importance, but the Queensland pine beetle Calymmaderus incisus Lea and the common furniture beetle Anobium punctatum (De Geer), a native of Europe, are of economic significance.
Aspects of the biology, behaviour and management of the Queensland pine beetle and the common furniture beetle in Queensland are discussed in this article.
Queensland pine beetle Calymmaderus incisus
Description
The adult beetle is oval in shape, about 3 mm long and 1.5 mm wide, the general colour being a shining reddish-brown. The antennae terminate in a three-segmented club. The body surface is covered in fine hairs and has numerous minute punctures, which are not discernible to the unaided eye. The legs can be tightly folded against the body.
The egg is white, spherical, 0.4 mm in diameter and is just visible. The larva is soft-bodied, curved, wrinkled, and creamy white with dark-brown mandibles. When fully grown it measures 4-5 mm in length and 1.5 mm wide. The body is clothed with numerous fine hairs. The pupa is soft, oval, creamy-white and measures 3.0-3.5 mm in length and 1.5 mm wide.
- Figure 1. Larvae of the Queensland pine beetle can reduce susceptible timber to fine gritty cigar-shaped pellets.
- Figure 2. Adult common furniture beetle Anobium punctatum.
- Figure 3. Life cycle of an anobiid beetle.
Distribution and biology
The Queensland pine beetle is a small native beetle which is widespread in Queensland. It has, in the past, caused significant damage to timbers only within the area limited by Murwillumbah (New South Wales) in the south, Bundaberg in the north and west to the Great Dividing Range.
Live adults are found only in the period October to February. Eggs are laid in cracks of susceptible timber and larvae hatch in a few weeks. Larvae can burrow long distances in the host timber and only the larval stage is responsible for destruction of timber. The tunnels run with and across the grain, giving a honey-combed appearance. The tunnel is loosely packed with frass which if viewed under a lens is seen to consist of cigar-shaped pellets made up of the chewed wood. When rubbed into the palm of the hand it is fine and gritty, quite distinguishable from the frass of Lyctus, which is soft and silky. Frass is sometimes ejected in small amounts through flight holes. Before pupating, the larva moves closer to the surface and constructs a pupal chamber. The development period for larvae is usually three years. Mature larvae pupate and adults emerge leaving a circular 2 mm hole in the timber surface. Painted surfaces or wall sheeting materials may be penetrated during emergence. It is a very slow working insect, and may take many years to cause extensive damage. Adult beetles live for up to four weeks.
Damage
The Queensland pine beetle is a pest of hoop pine timbers and rarely attacks other timbers. The beetles attack exposed (without paint or varnish finish) susceptible wood in housing and, less commonly, in furniture. Attack is most serious in old homes of more densely populated areas. Reports of damage have become less frequent over the past few decades, probably because of changes to building practices. Susceptible timber, if left untreated, will be reinfested until it is completely honeycombed and has lost most of its strength. These beetles are most commonly found attacking pine floors and walls, but are rarely found in roofing timbers. Typically, only some boards, or zones within boards, are attacked, particularly the sapwood. The adults emerge mainly from the underside of floors, so that boards which appear quite sound from the top may be riddled with holes underneath.
In very old structures, it is likely that any infestation has died out naturally as the susceptible material was exhausted. In these structures painted wall boards often have a dimpled surface, with no new holes. This indicates an extinct infestation.
Activity of infestations may be checked by:
- removing and dissecting timber to find live larvae, or
- marking out a few squares (sides about 100 mm) on infested surfaces and counting the enclosed holes. Mark in June or July before adults emerge. In January or February these squares should be checked for the presence of new emergence holes.
Neither method is completely reliable as only part of a structure may be infested at any one time.
Management
The economic significance of prevention, as compared to cure, is appreciated by manufacturers and property owners who have experienced trouble through infestation by wood-boring insects.
Damage is prevented in several ways:
- by limiting insect access to the timber using covering or enclosing materials.
- by painting or polishing with varnish or wax;
- by preservative treatment with a preservative registered under the Timber Utilisation and Marketing Act 1987 (TUMA).
These measures are implemented during building construction as a requirement of the Queensland Variation of the Building Code of Australia (BCA) - Qld B1.3 (f) (iv).
Eradication (cure) of most borer infestations is not a simple matter, and often demands perseverance. Any one treatment will not give complete success, therefore, repeated treatments are required. The necessity for treatment and type of treatment depend on the circumstances. For valuable furniture or, rarely, house infestations, gas fumigation may be used. This procedure can only be carried out by licensed operators. Small items are also disinfested by placing them in a freezer for at least one week. Fumigation and freezing will result in complete eradication, but will not prevent reinfestation.
The larvae of the Queensland pine beetle are usually well entrenched within the wood, but move closer to the surface to pupate. This occurs in spring and summer, so these periods are best for attempts at treatment. Active infestations can be destroyed by brushing or spraying unpainted or bare timber surfaces with a registered oil-based insecticide. A product containing permethrin is commonly used. Painted surfaces cannot be penetrated by insecticide and should be sanded prior to treatment. Badly damaged timber should be removed and replaced with immune or pre-treated timber. The first treatment should be made in early spring, followed by at least one other treatment during the summer. A careful watch will then be required, and treatments repeated in successive seasons until the attack is arrested. Because drywood termites are often associated with old borer infestations, treatment of the lower surface of flooring with a registered oil based insecticide each 4-5 years is generally recommended.
Common furniture beetle Anobium punctatum
Description
The adult is about 4 mm long and usually chocolate brown with reddish-brown legs. The head is concealed beneath the hooded ('cowl-like') prothorax and the antennae end in a three-segmented club. The beetle is covered with fine yellowish hairs and has longitudinal rows of pits on the forewings. The adult is larger, more rectangular and not shiny like the Queensland pine beetle. Microscopical examination is usually required to distinguish between the two species. The characteristic shape of the head and prothorax readily distinguish the common furniture beetle from the powderpost beetles, Lyctus spp. (see Figure 2). The eggs are ovoid in shape and easily seen. The larva is greyish white with a gold-brown head and chestnut-brown mandibles. It is covered with fine hairs. The larva is normally hook-shaped, but curls into a tight ball when removed from its tunnel.
Distribution and biology
The common furniture beetle is a small exotic beetle. It is native to Europe where it is a serious pest of timber. In Australia, it has established in the southern states where it is a pest of exotic pine timbers. It has not achieved major pest status in the warmer climates of Queensland, and has been recorded only rarely from housing timbers, being found primarily in imported furniture. The biology of the common furniture beetle is similar to that of the Queensland pine beetle.
Damage
Attack is usually encountered in pine timbers, particularly those which have been in service for at least 20 years. The beetle will attack hardwoods such as English oak and infestations have also been recorded from spotted gum. Both the sapwood and the heartwood of some timbers can be infested. Radiata pine in New Zealand is very susceptible and this has led to mandatory immunisation when it is used for building construction or furniture. In Australia, however, there have been very few examples of such attacks despite the widespread use of this timber. The reason for this anomaly is unclear. Attack in buildings is generally heaviest in the damper areas including cellars, flooring, skirting boards and outbuildings.
Management
Treatments for the common furniture beetle are similar to those of the Queensland pine beetle.
Pine bark anobiid Ernobius mollis
Description
The adult is up to 5 mm in length and similar to a large common furniture beetle. When newly emerged it is covered with fine golden hairs, and appears to be golden brown in colour, darkening as the pale hairs are worn away. The elytra are smooth, distinguishing it from the common furniture beetle which has longitudinal rows of dark marks or 'punctures'. The wing-cases and other parts are soft and much less horny than in the common furniture beetle.
Biology
Development requires one year and adults are present only in the spring and early summer. The presence of bark is essential for development. Larvae may burrow long distances in the bark and wood and in the process may damage other materials in contact with the wood, for example, leather and plastic. Emerging adults can also cause damage by boring through veneer or other materials around the infested bark. The round flight hole is about 2 mm in diameter.
Damage
The pine bark anobiid is a pest of untreated exotic pine logs or log off-cuts which have bark attached. Occasionally, attack occurs around knots in boards but it is essentially a bark dwelling insect, sometimes causing superficial damage to outer sapwood. It does not cause structural damage and is of only minor economic importance.
Management
Attack is prevented by removing all bark from susceptible timber or logs. Where infestation is already present, the best method of control is removal of bark followed by a brush treatment of the infested wood with an insecticide.
Cigarette beetle Lasioderma serricorne
Description
The adult is about 3 mm long, with a light brown to shining red integument which is finely punctured and covered with very short hairs. The oval, whitish eggs are laid in and about food materials. Mature larvae are about 4 mm long, curved, hairy and pupate in silken cocoons covered with bits of foodstuffs.
Biology
Unlike the anobiids previously discussed, L. serricorne has a relatively short life cycle, as little as five weeks, and adults are active all year.
Damage
The cigarette beetle is a stored products pest, and is often found in pantry items such as breakfast cereals, dog biscuits and paprika. Some building or ornamental materials may be attacked, particularly some compressed fibre boards and ponga (New Zealand tree ferns) Cyathea spp. and Dicksonia sclerosa. As with other anobiids, the larvae cause most of the damage. Adults may emerge through covering materials, leaving small circular holes about 2 mm in diameter. This species is very common in Queensland, but is not a major pest of building materials.
Management
Infestations in some compressed fibre board can be managed with a brush or spray treatment with a suitable oil based insecticide. In some susceptible compressed fibre boards insecticides are incorporated during manufacture to prevent attack. Untreated insect-free susceptible materials can be painted or varnished on all surfaces to prevent infestation.
Ponga ornaments can be disinfested by deep freezing for a few days. Reinfestation can be prevented by thoroughly coating the ornament with clear varnish.
Summary
The Queensland pine beetle Calymmaderus incisus Lea and the common furniture beetle Anobium punctatum (De Geer) are of economic significance as pests of, primarily, pine timber in buildings in Queensland. Changes to building practices have decreased the risk of attack to timber-in-service and reports of damage have become less frequent. Eradication of most borer infestations is not a simple matter, and often demands perseverance. The biology, behaviour and management of these beetles in Queensland are similar, but the common furniture beetle is found primarily in imported furniture. The pine bark anobiid Ernobius mollis (Linnaeus) and the cigarette beetle Lasioderma serricorne (Fabricius) are of minor importance.
Source of information:
Peters, B.C., King, J. and Wylie, F.R. (1996) Pests of Timber in Queensland. Queensland Forestry Research Institute, Department of Primary Industries, Brisbane, 175 pp. Available from Queensland Government Publications
Related DPI&F notes
Ants in timber in Queensland
Borers and the householder in Queensland
Drywood termites in Queensland
Powderpost beetles in Queensland timber
Subterranean-termite-baiting systems
Subterannean infestation in buildings
Subterranean termites in Queensland
Information contained in this publication is provided as general advice only. For application to specific circumstances, professional advice should be sought. The Department of Primary Industries and Fisheries, Queensland has taken all reasonable steps to ensure the information in this publication is accurate at the time of publication. Readers should ensure that they make appropriate inquiries to determine whether new information is available on the particular subject matter.
Last updated 24 January 2007
