The Borer (common house) are pests of major economic importance in New Zealand and the significance of this has is not yet been adequately recognised. With New Zealand houses getting older the damage to timber accumulates and with these attacks the timber becomes progressively weaker. It is not uncommon for weather boards, floorboards, joists and other structural timbers to need replacing due to weakness caused by borer. The borer larvae create holes and labyrinths which allows water to penetrate many timbers and increases rot by fungi.
Borer larvae (woodworm), spend after 2 - 4 years tunnelling inside the wood and will then exit as the adult beetle via a round hole 1 - 2mm in diameter. The now adult borer emerge in order to breed, will not eat any more timber and will die within 3 - 4 weeks.
The other borer known as the Longhorn borer. These beetles include the Two-Toothed Longhorn, Ambeodontus tristis, Burnt Pine Longhorn and Huhu grub beetles. The larvae of these beetles feed on dead timber. The Two-Tooth is a major pest that damages timbers in buildings and in the timber industry.
There are 180+ Longhorn beetle species endemic to New Zealand. The Longhorn family is a large and diverse beetle family. They are long, with narrow shaped bodies and very long antennae. Adult Longhorn beetles may be found on flowers where they feed on nectar. The huhu beetle is one of the largest New Zealand beetles.
The labyrinths and flight holes created by the Longhorn beetles are much larger than house borer and this is because of Longhorn beetles larger size. The Two-Tooth borer larvae often cause severe damage to rimu floors and other timbers. The Two Tooth borer flight holes are approximately 3-4mm across and the flight holes of Longhorn beetles tend to be oval rather than round.
The damage caused by the Two Tooth borer beetle larvae and other Longhorn beetles can be controlled by the same treatment as for common house borer.