COMMON HOUSE BORER EUROPEAN (WOODWORM)
Anobium Punctatum
ANOBIUM PUNCTATUM is a pest of major economic importance in New Zealand, the
significance of which is not adequately recognised. 3 - 5mm long,
dark-brown/black in colour, it is clearly identifiable with the humped (hooded)
prothorax which covers the head.
After 2
- 3 years spent tunneling away inside the wood as a larvae (grub), the adult
beetles will exit via a round hole 1 - 2mm in diameter. Cutting out this
trapdoor is their final wood destroying act. They emerge in order to breed, will
not eat any more timber and will die within 3 - 4 weeks.
LIFECYCLE
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When selecting a site for oviposition (egg laying), females appear to
recognise the presence of starch in the wood, a vital ingredient for larvae
survival. Eggs are NOT laid in starch free wood. |
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Larvae eat and absorb cellulose only when it is rendered digestible by fungi
and micro-organisms present in the wood itself and without which the borer
larvae would starve. |
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Humidity plays a very important part in the incidence of timber
infestations. Damp, humid areas create ideal conditions for borer attack.
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Most districts of New Zealand provide the perfect climate for borer.
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WORST AFFECTED AREAS: CENTRAL UPPER NORTH ISLAND particularly Waikato.
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LEAST AFFECTED AREAS: CENTRAL OTAGO. Hot dry climate will not support any
significant borer infestations. |
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World wide distribution of anobium has been effected by man himself.
Primarily with the relocation of infested furniture and also the widespread
use of untreated softwood timbers right through into the late 50's and early
60's. |
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Anobium Punctatum always lays her eggs during the flight season (October -
February in New Zealand). Eggs are 0.55mm long and 0.35mm wide. Average
number of eggs is 30. |
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Eggs are always laid in cracks, crevices, end-grain timbers, often into old
flight holes, never onto sealed, painted or varnished surfaces. |
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Females may mate 3 times or more during the course of egg laying. Mating
normally takes place on the surface. Sometimes this will take place with the
female in the hole and the male on the surface. |
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Larvae bore directly into the timber through the bottom of the egg sack. 6mm
long when fully grown, larvae will spend 2 - 3 years chewing away inside the
wood before eventually working to a position just below the surface
(September - October in New Zealand). At this point they hollow out a pupal
cavity which allows for the change over from larvae through pupae and into
adult beetles, climaxing with the adult beetle cutting out an exit trapdoor
onto the surface. |
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The
exiting urge is of such magnitude that they frequently gnaw out through
paints, wallpapers, varnishes, linoleums, wallboards and plasters. They have
also been known to exit through sheet lead and formica. |
NEW TECHNOLOGY
OF WOOD CONSERVATION
Without
doubt Anobium Punctatum was the prime motivator both here in New Zealand and
around the world for the establishment of a good sound and
reliAnobium larvae are seldom, if ever, found in fresh milled timbers, but
require some condition for their development which is not present in wood until
it has aged, or in some other way differs from new timber. able timber
treatment; helping to place New Zealand among the world's leaders in the field
of timber protection. Ask us how!
