Evening Republican, Volume 19, Number 267, Rensselaer, Jasper County, 10 November 1915 — Batattle Man Must fight With Insects [ARTICLE+ILLUSTRATION]

Batattle Man Must fight With Insects

HE foremost scientists of the world have been agreed for the last decade cM that the crucial struggle of humanity will not be that of nations warring in for territory which each A 1 a a envies the other, but will v(4 be a c °l° Sßa l battle to 7 '* keep from being driven off the earth itself! And in*this battle it will be mankind against bugs! By its fecundity, its enormous comparative strength—sometimes equivalent of what would be, if the bug were as large as a horse. 1,000-horsepower —and in its Inextinguishable passionate and concentrated will to live and its enormous adaptibility the insect kingdom makes the human race appear incredibly inefficient. Civilization has for the last twenty years and more been steadily overturning the balance of nature, which has kept the insect kingdom down, and this scientists throughout the world have recognized. Within half that time what amounts to a world-wide organization has been formed to find and make known to all who care the best ways to cope with the fastgrowing swarms which menace humanity. It is recognized that only by a tireless, long and costly and dangerous struggle will man be able to retain his dominance and freedom to develop his world. The latest warning of this peril to humanity has been sounded in a most remarkable fashion by Prof. C. A. Ealand, one of the foremost entomologists of the world and the late principal of the East Anglian college of agriculture of England. Professor Ealand begins his remarkable work, which he calls “Insects and Man,” with the following statement: “It is fortunate for man that the insect world is a house divided against itself. Except for this check the human race would be extinct in five or six years.” The fecundity of many insects is enormous. Huxley estimated that, mishaps apart, a single green fly would in ten generations produce a mass of organic matter equivalent to 500,000,000 human beings, or as many as the whole population of the Chinese empire! From the earliest times man has suffered from insect damage to his crops, his live stock and himself. Locust plagues rivaling those of Egypt have come to man from time to time. The United States suffers damage annually to the extent of >40,000,000 owing to the depredations of the Hessian fly; the cotton boll weevil causes an annual loss of >30,000,000; the codling moth >15,000,000, and the chinch bug >7.000.000. Add to this the damage done by gypsy and brown-tail moths and the San Jose scale, to say nothing of the host of minor pests, and the total assumes alarming proportions. 0 The struggle for supremacy between Insects and man is a very real one the world over. But only by ceaseless struggle can man keep his dominance. In his fight against insects and bugs he has arrayed against him an incredible fecundity and power of destruction. The majority of people—unscientific people, that is—says Professor Ealand, think that the locust is the most destructive insect. This is partly because of the Biblical plague having been fixed in their minds. The locusts have done more damage in South AfHca and hindered agricultural prog-

ress there more than anywhere else in the world. In one winter alone the locust damage in South Africa was estimated at >5,000,000. To cope with the insects the government has established a central bureau for watching them. Flights can be predicted and measures taken to minimize them. In the latter half of 1912 locust swarms did >10,000,000 damage in our own island of Visaya, in the Philippines. While the locust is prolific the cotton weevil beats him. Professor Ealand estimates that one weevil laying her 139 eggs by June 10 would probably bring half that number—say 75—to maturity by June 29. There are at least four generations in a season. and the second generation would number about 2,450; the third 85,750, and the last and final generation 1,001,250, or a total of 3,089,520 individuals as the progeny of a single pair of weevils and their progeny in a season. That is to say, one weevil for every square foot of area in a 75-acre field. As over 50 per cent are destroyed by natural conditions, it is doubtful if the actual increase in one season from a single pair ever exceeds 2,000,000. Alarming figures in all conscience, exclaims the entomologist This is only one of a vast number of insects that man has to fight against Next come the disease carriers. First in deadliness is the mosquito, which infests man with malaria, yellow fever and filariasis. Many parts of the tropics and localities otherwise most desirable are practically uninhabitable to civilized man, owing to the ravages of malaria. Malaria has been held responsible for the wiping out of the ancient Greeks. Not health alone, but man’s very pockets are affected by this overmastering incubus. The mosquito plague has been responsible for arresting the development of the whole state of New Jersey. Malaria is a country rather than a town disease. It was once supposed to be caused by dwelling in damp and marshy places, and even now the belief dies hard in the minds of many people, but it has been proved beyond dispute that by the bite of infected mosquitoes, and by that means alone, can this dread disease be transmitted from man to man. Various estimates have been made as to the number of bacteria that may be carried about the body of a single healthy, active fly. One investigator, Torry, puts the number at 28,000,000 in its intestine and 4,500,000 on the outer surface. Esten and Mason, by careful experiment, found that the number of external bacteria varied from 550 to over 6,500,000; other observers have put the number as high as 500,000,000 per fly. The numbers seem incredible. That one louse fly can carry about its body as many as 500,000,000 germs is almost beyond belief, vet the estimated number is not the result of guesswork, but of careful experiment. Looking at the matter from the most favorable point of view, and supposing each fly to carry only 550 bacteria from place to place, the supposition, says Professor Ealand, is not pleasant. The dreadful infantile paralysis has been discovered to be carried by the stable fly. Then there is the sleeping sickness, which is carried by the tsetse fly. Whole districts of Africa are absolute-

ly uninhabitable because of this disease. Come next the armies of ticks. It has been shown by experiment that one variety of these which feeds upon human blood will weigh after a meal ten times its original weight. Some species increase to thirty times their original weight. Imagine, says Pro* fessor Ealand, a hungry 200-pound man weighing 6,000 pounds after a single meal, or even after many meals! Relapsing fever, spotted fever, a peculiarly deadly disease called verruga, are given man by ticks. Then there are the lice which carry typhus and a form of inflammatory rheumatism, and the fleas, which transmit plague to man. As for the hosts that attack the domestic animals and transmit to them disease, were it not for natural checks and the vigilance of man there would not be a single animal left in the world within ten years! It is this matter of natural checks, the equilibrium which nature has provided against these most prolific of her children, that is now most worrying the scientists. Up until comparatively recent times great quantities of insects were used for medicine, for dyes and so on, but this use has steadily lessened, and with the lessening naturally the insects have increased. The practice of the control of insect pests by their natural enemies is onp of modern times, for the earliest record of work on anything approaching a commercial scale, dates back by 25 years. It is based on the assumption that all nature is in a state of equilibrium —that is to say, that all life, in its native home, is kept in check by other forms of life which prey upon it More than thirty distinct parasites and seven kinds of predatory beetles have been introduced into the United States to wage war on the gypsy and brown-tail moths, says Professor Ealand. It will be recognized, says Professor Ealand, that unless a parasite shows greater fertility than its host, its power of controlling the latter must be very greatly diminished. In this connection nature has come to the rescue in a marvelous manner by endowing many of the parasites with the power of “polyembryony,” a phenomenon that is unique in the animal kingdom. Parasites so endowed lay eggs similar in external form to those of their less fortunate relations, but from each egg emerges in due course not one larva, but a number of larvae, and by this means their fertility is much increased. A second and still more modern method of natural insect control is carried into effect by means of fungoid disease of insects. These fungoitfs are scattered over large plantations with a dusting machine. All the insects infected carry the disease to their numerous relatives. The fight, indicates Professor Ealand. is only at its beginning. Man will probably win, but even if he does the bug, through its persistence, will outlive him.