BORER BEETLES SOUGHT FOR SCIENTIFIC STUDY

Gisborne Herald, Volume LXXV, Issue 22820, 15 December 1948, Page 15

BORER BEETLES SOUGHT FOR SCIENTIFIC STUDY

A Wellington laboratory is making a national appeal to buy borer beetles for research purposes. This appeal follows a local effort made during the borer flight season last summer when thousands of beetles were sent in by men, women and children who brought containers containing anything from a few shillings to several pounds worth. The decision to make the appeal a national one was to obtain data on the emergence in different localities and to observe any variations in the species which might he found. Enormous Damage Caused The common borer beetle does millions of pounds worth of damage annally yet he is not recognised by many householders, as most of the damage is hidden and the flight season lasts only a few weeks. In the first stages of attack damage is mainly to sub-floor areas and places like the laundry where moist conditions prevail. Once established, the beetles attack furniture and fitments, joinery etc., and their characteristic round holes appear. These are emergence holes. After mating the beetles frequently return and lay their eggs back m the hole or in crevices or on the rough surface of the wood. The life cycle from egg to beetle takes at least three years, and most of the insect’s life is spent in the larval or grub stage. In the laboratory, first of all the beetles are sexed, the males being sorted from the females, and any dead or injured beetles removed. Effect on Timber Studied Equal numbers of male and female beetles are put into similar cages, each containing a variety of timber used in the New Zealand building industry. Other cages contain equal numbers of insects and the same types of wood, but in these cases the wood has been treated with various chemicals used against wood destroying insects. Male and female insects are always included, as the female will lay one i small batch of eggs, then mate again j perhaps several times between egg laying.

A female beetle before dying will lay between 30 and 40 eggs, and if it is realised that half of the borer holes seen in the flight season are those of female beetles, then some idea can be gained of the extent to which a property will be attacked before the next flight season.

The tests being conducted with these captured beetles will show the susceptibility of various building timbers to attack and the degree " of protection achieved by the use of various chemicals.