TERMITE SCARE

Evening Post, Volume CXXVII, Issue 19, 24 January 1939, Page 11

TERMITE SCARE

UNWELCOME GUESTS

WOOD AS A DIET

The scare is periodically raised that New Zealand has been invaded by white ants and that they are doing untold damage to timber. In yesterday's "Post" a message from Auckland stated that that city had been favoured by the establishment of a colony of these insects^—"millions of subterranean termites" having damaged a house to the extent of £150. The termite is neither white nor is it an ant, but the name white ant is a popular one for these insects—some of the most primitive in the world — and it is a name not likely to be dislodged. Termites are among the most destructive of insects, but fortunately for New Zealand it is in the Tropics that they thrive best, so they are never likely to become a real pest in this country. But, as a matter of fact, it has 'as yet to be proved that the ravaging insects unearthed in Auckland were termites. The Cawthron Institute at Nelson, to which samples have been sent, will decide that point. There are many different kinds of termites, and they vary much in size. Some build gigantic nests above the ground, while others, like the true ants, live a strictly subterranean existence. Owing to their destruction of buildings, fences, and all kinds of ] woodwork, as well as of growing trees and plants, termites constitute one of the greatest problems in the development of countries where they abound. This destructiveness, however, is not shared by all termites. The obvious answer to the question as to why termites eat wood is because they are hungry and it is their natural diet. But recent investigations have thrown some very interesting light upon this. The principal constituent of wood is cellulose, which is a most indigestible material. In fact, cellulose can only be digested by mammals that harbour certain intestinal bacteria,. or by certain invertebrates that secrete an enzyme (cellulase) capable of breaking up woody fibre. Protozoa provided with this enzyme j have been found in the intestines of all the wood-eating termites, so the termites are able to chew one's wooden house to powder and' not suffer from indigestion. Deprive a termite of the friendly protozoa inside it, and it will die within a few days although' fed on a normal wood diet. Quite a number of insects besides termites attack wood, there being a 1 number of borers which do untold damage to timber. New Zealand, unfortunately, is not free from their unwelcome attentions, and specialised work is at present being carried on at the Cawthron Institute with a view to checking the ravages of the various boring insects. The termite is certainly not needed in addition, but authorities, although admitting that some may occasionally be imported unwittingly from Australia in wood brought from that country, are not alarmed at the prospect of termites becoming firmly established in this country and becoming as, great a nuisance as they are in tropical Australia for instance. Climatic conditions, it is considered, are against this happening.