INSECT PEST.

Timaru Herald, Volume CXXIII, 12 January 1927, Page 12

INSECT PEST.

AND THEIR CONTROL. CHAT WITH DR. TILL YARD. By Telegraph—Tress Association. NELSON, January 11. Dr. Tillyard, Biologist, of the Cawthron Institute, who has been on an extended visit to England, Europe and. America, in the interest of scientific research, returned to Nelson this morning; The result of his investigations have been embodied in a voluminous report which will be submitted to the ActingPrime Minister. The main report is confidential and cannot be disclosed untii released by the Minister. Dr Tillyard to-day said that he was at liberty, however, to mention a few points connected with his tour abroad. At the request of the Prime Minister and the Hugh Commissioner, he liad extended. his stay in England by an extra month to attend the Imperial Conference, as New Zealand’s representation on the Research Committee. Ho was the only New Zealand representative on that committee. Dr_ Tillyard said that liis main investigations, when abroad, proceeded on various lines of entomological research in the shape chiefly of inquiries into the possibilities of the biological control of the blackberry and other noxious weeds. He had met with considerable success in discovery insects which attacked the blackberry, more or less efficiently, and he was arranging for their introduction into New Zealand, under proper safeguards. * I Of the insects referred to-, it very early became apparent to the investi- ■ gator that such an enonnous problem could, not bo attacked wilth a hope of solution without large financial backing, so there was drawn up and submitted to tlio Empire Marketing Board a fit-home dealing with the question. The

problem was of immense importance because other parts of the Empire were affected in a similar wav to New Zealand. South Africa and Australia were experiencing similar difficulty in respect to growths akin to the noxious weeds of New Zealand. Those two countries had approved of and accepted a scheme put before them, and the final result had been an offer by the Empire j Marketing Board, of a sum of £2OOO a year, for five years, on condition that I the New Zealand Government also gave £IOOO a year for five years, and the Cawthron Institute did the same. This would mean a grant of £4OOO a, year for five years, or £2Cf,OOO in all. This offer, Dr Tillyard said, was ac- ! cepted by all concerned, the outcome being a good workable scheme for a thorough testing of the possibilities of the control of Iblackberry, gorse and other noxious weeds, by means of their insect enemies. The scheme, added the doctor, must be confined to insects and fungoids and must not be introduced, on any account, as the risk in that connection, of great damage being done, was very serious. Another scheme submitted to the Empire Marketing Board was iki the nature of a suggestion that there should be Empire research into the question of pasture efficiency. New Zealanders are familiar with the recent discussions into the matter of deteriorated pastures. These should be extended to thi!s Dominion and the Board agreed with the proposal. It offered £2OOO a year for two years, on similar conditions to those outlined 'in, connection with noxious weeds research. Details of both schemes would require further working out. Referring to the problem of the con- : trol of earwig Dr Tillyard mentioned ; that considerable advance had been ; made in regard to this question. He had however, brought back with him a. i large supply of the puparia of the para- ; ’ sitie fly, which attacked the earwig, and he was hopeful of getting it acelimatised_ in New Zealand. A very interesting fact which he had , discovered in England was that ' this } parasitic r fly hid in its turn a secondary ;

! parasitic fly called the disbrachys, i little moth that attacked the puparia This moth was a parasite of the wax moth which did so much damage in bee hives; it had therefore’ been decide! that earwigs did the most good, anc tlie dibrachys would have to be kept out. Dealing with the question of the eradication of gorse, Dr Tillyard said In had obtained large supplies of an insecl which almost entirely prevented gors« from seeding, and m England it was al present being successfully used in a solution of tlie problem. Work had also been done in connection with the eradication of othei weeds—ragwort, St. John’s wort (which was in particular very bad in Australia) and foxglove (which threatened to become a very poisonous weed in many party of the Empire). The eradication of convolvulus had also been studied and it was the opinion of botanists that this plant was going to be one of the worst pests in tlie worfet during the next fifty years. At present no satisfactory solution was in sight. Another large consignment of green lace wings, specially treated for the control of aphis blight on various trees, had been brought out, and if it were possible to acclimatise them in in New Zealand, he thought chat a, lot of good would accrue. Generally speaking Dr Tillyard affimed that if tlie present line of modern research in connection witli the eradication of the weeds referred to were not successful, it would be a pretty bad lookout, because there seemed no othei 3 way of tackling the problem. Dr Tillyard said he had found in-' stitutions in England workilng on similar lines to the Cawthron Institute. He noticed particularly that the Rotliamsted experimental station,' at Harpenden, near London, liad developed immensely during tlie past six years. I