NATURE NOTES

New Zealand Herald, Volume LXIX, Issue 21248, 30 July 1932, Page 1 (Supplement)

NATURE NOTES

INSECT' ENEMIES

BY J. DRUMMON'D F.L.S., F.Z.S.

The grass grub, the aphis, the codlin moth, the scale insects and the borers are troublesome in New Zealand, some of them claiming a heavy toll. In spite of this, the New Zealand public do not understand that insects are their dangerous rivals for possession of the best the Dominion produces. Outside the walls of the Cawthron Institute, perhaps, there is no realisation of the present state of affairs or of inevitable developments. The position is not very bad, but it will become worse, and it is wiser, to face .it now than later. This is borne in upon everybody who reads the latest work by Dr. L. 0. Howard, formerly Chief Entomologist of tho United States Department of Agriculture. For fifty-four years he carried out vigorous campaigns against injurious insects in the United States, his operations providing methods and weapons for the war in all parts of the world. Fostering high ideals, he took an exalted view of his lifo work. Ho believed that every entomologist helped mankind, and that their efforts should command recognition and respect. He has been described by another entomologist as the greatest entomologist in the world to-day; and those who know what he has done, and those who meet him for tho first time through the pages of " The Insect Menace," readily understand why he is ranked among great men. Written in a chatty, conversational, easy style, but highly dramatic, his book depicts the insects as strong, industrious, resourceful, eager, militant beings, boast-' ing ancient lineage, but adapting themselves to every change of condition. He shows that the insect type is very many millions of years older than the vertebrate type, of which the human species is the latest development. The insect type, therefore, has been tried out thoroughly under the world's conditions, while the human type, comparatively, is in its infancy. Many types of beings, small and great, have been developed and then blotted out; the insect type has persisted through every change of climate and every cataclysm. The human species, in spite of physical disadvantages, leapt to tho fore with a speed the world previously did not witness. Yet Dr. Howard solemnly warns people that the human type naay be placed among .Nature's experiments that have failed j it has not been in existence sufficiently long to be completely tried out, Tho unprecedented progress of the human species, its increase and its wide distribution, so far from deterring the insects, help their spread and multiplication almost beyond measure. Human beings use their brains to feed the countless members of their own species. In this endeavour they feed the daily increasing hosts of their enemies, the insects. To produce the most abundant * food supplies with tho least possible loss of time, men often grow their crops in the best way to increase crops of insects. New Zealand in the early days was an object lesson in this direction. Crops and vegetables, when first produced here, were an astonishment to the delighted insects. The numbers of caterpillars increased with the new food supplies, and they marched from.field to field in great processions, leaving the abomination of desolation behind them. Dr. Howard's view of the position is not a dismal one. He doesnok regard it as" desperate." He does not believe that the human species will go down in defeat before the insect type. What he does believe is that, unless people reahse tho danger, try to learn everything that can be learnt about injurious insects, and deeply study applied entomology, the struggle will continue for ages. By studying insects, people learn the little creatures' weaknesses, discover their natural enemies, and know where they may be assailed most effectively, vlf Dr. Howard had £500,000, he states, he would set aside about £50,000 for his three daughters and devote the balance to applied entomology, providing that the income should be spent on only basic projects. The cotton boll-weevil went from Mexico in cotton taken afcross the Rio Grande to be ginned. The European corn-borer was in broom-Corn imported from Hungary. The alfalfa weevil was transported in alfalfa straw used for packing. In the same way many injurious insects came to New Zealand, sometimes from far afield, often from our' next-door neighbour the Commonwealth, 1200 miles across the Tasman Sea. The small cabbage-white butterfly of Europe and the Old Country is the latest addition to New Zealand's list of pestilental introduced insects. Dr. Howard does not mention it in this book, but it was reported from North America seventy-two years ago. Its distribution, no doubt, is made possible by its eggs being carried on plants taken to New Zealand and to tho United States. Dr. Howard does not aim at sensational effect. He simply presents the hardest of hard facts, but he does so dramatically. He is a somewhat rare being, a man of science who can write well and interestingly. A reviewer confesses that " The Insect Menace." 'although its title is plain, rivals the best murder mysteries tn holding the attention of readers. A copy has been sent by the publishers, the Century Company, New York <and London. Mr. E. T. Frost's notes, straight from Nature's book, always aro interesting. His knowledge and love of natural history make his trips into the country doubly interesting to him. Motoring along the main highway near Kaitaia, North Auckland, he saw a big white pig rooting in a grass paddock for earthworms. It did not have all the results of its labour. About twelve mackerel gulls surrounded it. dashed in every time it raised its snout and took all the earthworms in sight. Becoming irritated by the persistent birds, it often moved to fresh ground hurriedly, but its unwelcome companions kept close, and it. was no better off. It was riot seen to snap at them, but its demeanour showed that, it was very angry at the attention they gave it • Destroying earthworms may be a doubtful benefit to the land, but Mr. Frost pays a compliment, to the mackerel gulls for their work in destroying crickets. These, he states, were fairly plentiful in the past summer. Thousands of mackerel gulls lined the roads and swarmed over the grass paddocks, making prodigious meals Of tho insects, taking millions of them. Watching them following the plough was like looking at a movie picture, but was more real and interesting. Several hundreds followed close behind a ploughman, almost at his heels. As the foremost gulls were busy picking up earthworms and crickets they were delayed, and the front places were continually filled by those behind. As the ploughman pushed on, there was a continuous flight of gulls from the rear to tho front, making a pretty and unusual scene. Mrs. Frost mentions a pukeko that has chummed with fowls in a fowl-yard. It knows the morning and evening calls to. meals as well as the fowls do, and is as tame as they are, never trying to fly away. A woka that occasionally appears in the, fowl-yard seems to have a guilty conscience, running off at the least, alarm and going toward its cover, into which it darts if it fears danger. " Tt is a likeable rogue," Mr. Frost writes, " and as long as it does not take too fnany eggs it will be welcomed to the fowl-yard community."