POISONING OF PESTS

Wairarapa Times-Age, 15 August 1938, Page 3

POISONING OF PESTS

NATURAL BALANCE UPSET. USEFUL ANIMALS DESTROYED. That the wholesale poisoning of pests such as rabbits, grasshoppers and other destructive animals and insects defeats its own ends, and results in their increase rather than elimination, is the opinion held by many authorities in this and other lands. It is asserted that the poisons used —arsenic, strychnine, phosphorus and so on—kill out, or greatly reduce, the parasites which under natural conditions keep the pests in check. Freed from their parasites and not greatly reduced in numbers by poisoning, the pests are more healthy and prolific, and soon present an unsolvable problem. It was a noticeable feature of rabbit poisoning with phosphorised pollard baits, and poisoned grain and jam in New Zealand, that while the rabbits were never exterminated by this method, the native birds which picked up the baits were practically wiped out over big areas, and the rabbits’ natural enemies, cats, stoats and weasels, which no doubt ate the poisoned animals, were greatly reduced in numbers. As a consequence of the reduction in bird life, insect pests which a decade or two ago were looked upon as practically harmless have so increased in numbers that they are now a serious menace in some districts. The results of upsetting the balance of Nature by wholesale poisoning may well,have repercussions much more serious than we can foresee. The cure may thus be much worse than the disease.