Target Pest offers pest control services for all three species of borer (sometimes known as bora or woodworm) and other wood boring insects that affect New Zealand timbers. Larvae of the beetles eat their way through the interior of wood before emerging via flight holes as adults to mate and begin the life cycle over again. All untreated timbers can be attacked.
TARGET PEST technicians will survey the extent of infestation and apply penetrating treatments with natural insecticide, which persists in the wood, killing insects as they emerge, and preventing re-infestation for at least five years in Roof & Subfloor Areas .
TARGET PEST technicians have had over 20 years experience in borer control and hold Approved Handlers Certificates, PMANZ registation and University Diplomas.
BORER (Bora)- WOOD BORING INSECTS
Borer is also known as Bora or woodworm. There are up to 7 species of wood- boring insects in New Zealand that might attack the timbers of your home or other buildings. The most common of these is the Common House Borer (Anobium punctatum) also known as Woodworm in the UK.
A close relative, A lavomaculatum is rarely distinguished from the Common Borer and may be the more common in Canterbury. The life cycles of these insects are similar. Adult females lay up to 100 eggs on bare timber or in old flight holes. The eggs hatch after 4-5 weeks and the larvae bore through the wood, eating it and using yeasts in their stomachs to help break down cellulose in the wood. After 3-4 years the larvae pupate in a chamber near the surface, then 4-8 weeks later the adults exit the wood by eating their way to the surface. The adults fly to find a mate and begin the life cycle over again. The females lay their eggs on bare wood,. The flight holes are approximately 2mm in diameter for Common Borer and 3-4mm for native borer. It is important that a thorough survey is carried out to ascertain the extent of any infestation. It is frequently the case that a few flight holes are visible on the exterior of painted weather boards, however when the boards are examined more closely the interior of the timbers are badly damaged and many flight holes are present on the interior surface.
Two-toothed longicorn (Ambeodontis tristis (Fabricus) is a much larger wood boring beetle that can be found attacking construction timbers. The flight holes are much larger, up to 7mm in diameter and often oval. The larvae of this beetle can attack harder heartwood and because of their larger labyrinths they can severely weaken structural joists and beams.
Borer larvae prefer the softer sap wood timbers to eat and damage. It is often seen in weatherboards or floor boards that some are heavily attacked and others untouched. The untouched timbers are likely to be harder heartwood. It is also the case that attack is more likely on the south side of a house and in the floor boards and joists. This is because borer prefer the cooler damper areas where the relative humidity is higher.
Borer Timber Protection
Target Pest provides timber protection treatments. Surface saturation with Tim-bor® (sodium octoborate) solution is environmentally friendly, odourless and long lasting. Treatment of timbers to remove borer infestation is the same for whichever species is present. Exposed timber can be treated with insecticides that penetrate the wood and will protect it for 5 years or more. Usually the floor timbers are attacked because of the high relative humidity in the sub-floor.
Target Pest can treat these exposed timbers to eradicate the borer and protect the timbers. Weatherboard homes in New Zealand are not always pre-treated and are often infested where the softer, non-heartwood timber has been used. Weather boards are more difficult to treat as they are not usually exposed.
Fumigation with methyl bromide will eradicate infestations but is usually only practical for pieces of furniture or properties that can easily be completely sealed. Methyl bromide has no residual action, so, following fumigation, treatment of the timber with residual insecticide is required to protect the wood from further infestation. Where fumigation with methyl bromide is not possible or practical, control is by treatment of exposed timbers and injecting of flight holes with residual insecticide as above.
Some treatments are solvent based and require it to penetrate the timber (i.e. Kerosene or Diesel) these materials are highly flammable and could have insurance implications should a fire occur after a borer treatment. They also are mixed with organophospate insecticides that have been taken off the market in other countries due to their carcinogenic properties. The manufactures of solvents do not recommend that they are sprayed into confined spaces such as roof and subfloor cavities.
Tim-bor® is water based and not flammable, it is safe for you and your house.
Formulated with a concern for the environment, Tim-bor is used for the control of carpenter ants, drywood termites, wood decay fungi and wood boring beetles. As water soluable borate powder, Tim-bor diffuses into the wood and acts as a wood insecticide, fungicide and preservative. Tim-bor won’t break down over time like most organic compounds, therefore offering longer lasting protection. Best of all, Tim-bor is virtually odorless and has no known resistance.
Timbor is a natural insecticide and fungicide that is widely used as wood preservative and protectant. It is composed of nearly pure sodium borate, a mined crystalline form of boron with comes from the earth itself.
Contact Target Pest to arrange a survey and quotation
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|Anobium (common borer)|
Insect: Hadrobregmus magnus (Dumbleton)* (Coleoptera: Anobiidae)
*Formerly known as Anobium magnum Dumbleton
Fig. 1 – Hadrobregmus magnus adult.
This insect is native to New Zealand and is present throughout the country.
Hadrobregmus magnus may cause severe structural damage to rimu flooring and subflooring
where ventilation is inadequate as moist, dark situations are apparently preferred. The infested
timbers may be reduced to a thin shell (Fig. 2). It is far less common in timbers in use than the
household borer, Anobium punctatum.
Fig. 2 – Rimu timber damaged by larvae of Hadrobregmus magnus
Description, life history, and habits
The adult is dark brown and has an almost cylindrical body. When the beetle is seen from above,
the head is completely hidden by the pronotum. The elytra (wing cases), which bear longitudinal
rows of punctures, are parallel-sided and rounded at the rear. Adults are 6-8 mm long and 2.5-3.0
mm wide (Fig.1).
The larvae are C-shaped and white. They have three pairs of short legs, a yellowish head, and
black jaws. Bands of small spines are present on top of the rear thoracic segment and all ten
abdominal segments. Xyletinus undulatus, another anobiid borer, also has small spines on the
last abdominal segment but the fully grown larva is much smaller than that of H. magnus. The
larva of the household borer, A. punctatum, is similar in size to that of X. undulatus but lacks
spines on the last three abdominal segments.
There is little published information on the habits of H. magnus. Forest Research Institute
records suggest that successful attack depends on prior invasion of the wood-rotting fungi
although larval workings may extend into sound wood. Alternatively, those conditions
favourable for H. magnus are coincidently favourable for wood-rotting fungi. The length of the
life cycle is not known. Pupation occurs just under the wood surface or beneath bark and adults
are known to emerge during May, June, and July.
Heavy infestations will probably require replacement of affected building timbers, and repairs
or alterations to ensure that other untreated timbers remain dry. Pretreatment of timber with
preservatives gives complete protection.