INSECT PESTS

New Zealand Times, Volume XLVII, Issue 10816, 4 February 1921, Page 7

INSECT PESTS

HOW TO COMBAT THEM. "BIG FLEAS AND LITTLE FLEAS." Dr Tilly ard has been paying special attention to the modern methods of scientific control of insect pests. In his opinion American practice was far above British in these matters, and he must take off big hat to the Americans. Ho made a selection of cases illustrating the general principles involved. The first was quarantine and fumigation at the ports of entry. In Honolulu the suga r-planters had thought it worth while to supplement the salary of the Government officers in order to secure £uily qualified men, and the museum of the .pests that had been detected and kept out wag -a most educative one. Various mechanical devices for catching or trapping insects were described, and spraying was also illustrated) by a picture which looked like a fire brigade at work, throwing spray over a high, forest the sap of trees w,as at one time believed to be of little use, but recently the Italian Government had had great success by this method, though it was being kept a close secret at present. The most successful methods of control, he said, were biological. -These wefre of two kinds, the selections of strains immune from disease, often the only possible method of meeting the ravages, and control of insects by their own insect enemies. Predatory insects often served to keep pests 'under control, and many such could be advantageously introduced into New Zealand. Big fleas have little fleas upon their backs, and very .many insects could be controlled by their own parasites. In introducing useful insects to a bo-uaitry, it wa s all important to see that their own parasites were not introduced at the same time: He had [brought to New Zealand an enemy of the woolly aphis, and they had successfully hatched out.