MENACE TO TIMBER.

New Zealand Herald, Volume LXIV, Issue 19558, 10 February 1927, Page 12

MENACE TO TIMBER.

RAVAGES OF HORNTAIL. PINE FORESTS THREATENED. URGENT NEED FOR ACTION. [BY TELEGRAPH.-—OWN CORRESPONDENT. ] KELSON. Wednesday. A serious pest threatens the pine plantations of New Zealand, according to Dr. Tillyard, of the Cawthron Institute. During the past few years foresters and timber millers in certain parts of New Zealand, notably round Feilding and in parts of the Marlborough Province, have noted with some .alarm the increasing prevalence of a large timber-boring insect, known as the giant horntail. This insect is a native of Europe and was almost certainly introduced originally into New Zealand in consignments of Oregon timber^

In its native forests this insectr is not a pest. It lias never been known to attack healthy growing trees, but would sometimes attack diseased trees still standing in the forests. More usually, however, it confined its attentions to fallen timber, laying its eggs in the wood, which soon became more or less riddled with the large galleries of the larvae. Occasionally infested wood was used inadvertently in houses or for making furniture with the result that perhaps years later the perfect insects would emerge and cause considerable alarm. Specimens From Seddoa.

Recently a resident of Seddon brought to the Cawthron Institute .some sections of healthy growing pine radiata of con* siderable size, badly infested with this insect. The wood had been riddled by tho galleries of the larvae, which were attacking the growing trees in the plan" tations.;,

" It appears," said Dr. Tillyard, "that man in his. unwisdom is supplying this insect with the very conditions needed to restore it to its previous size and dominance, by planting all over a new country, with a wonderful climate, immense pure stands of the very wood which it likes best of all, namely, pinus radiata. Unless steps are at once taken to check it within a comparatively short period of time the whole of the new forests of pinus radiata in New Zealand will probably be so heavily infested with giant horntail that the trees will have no commercial value.

Two Beneficial Parasites. "Thefre are two beneficial insects which prey upon the pest and keep it to a large extent in check in its native country," ho added- Every person who was jn any way interested in the future of pin us radiata in any part of New Zealand was vitally affected by this problem. What -was really needed was a fund of money large enough to enable an expert entomologist to be sent to Europe and America for a period of at least two years, with instructions to spend the whole of his time studying the problem and locating supplies of the parasites. These should then be shipped out to New Zealand in cut logs, and these logß would have to be placed in quarantine in closed insectaries such as those at the Cawthrpn Institute, where they could be' watched from day to day until they yielded up both the injurious insects contained within and also "the beneficial parasite?. The former would be all destroyed as they emerged, while the latter would be transferred at once to a selected small en? closure in one of the infected forest areas, say at Seddon, and an attempt would be madfe to get them acclimatised there. - Early Start Essential.

" In my opinion," concluded Dr. Tillvard, "the danger from this insect is so great, judging from the evidence now available, that a fighting fund of at least £IOOO is urgently required, and at qnce, in order that a start can be made in Europe during the coming year, thus ensuring that the first supplies of parasites will be received in New Zealand next December or January. There is no mechanical or chemical way of checking the pest and the oply hope i§ that the parasites when introduced into New Zealand will find the conditions so much.^o their taste that they will go ahead with great vigour. -j" ■ "It is a case of the European earwig over again? only the possibilities of disaster before us are infinitely greater as they, involve the possible complete failure of extensive sehemes of planting of pinus radiata." i •=— v. 1