Puslapio vaizdai



Author of "Mr. Hobby," etc.

VERY quietly, without the call of the tion has ever occurred in Europe, Asia,

trumpet or the booming of guns, a strange and terrible warfare is being waged in New England, in which the casualties of a single summer day probably run into the millions. For several years Uncle Sam has unobtrusively been gathering his mercenaries for this struggle from all parts of the world. There are warriors from France and from Germany, from Russia and from Japan, fighting, so to speak, shoulder to shoulder, or, rather, wing to wing. The martial host numbers myriads.

The enemies against which the struggle is being waged are the gipsy- and the brown-tailed moths, those terrible destroyers that threatened totally to defoliate New England, and bade fair to spread their devastations far beyond its borders. The mercenary army is composed of insects the very existence of which is dependent upon their cunning effectiveness as moth-slayers. The lives of these minute warriors are consecrated to slaughter, and so well are they thriving at their sanguine task that, as far as the moths are concerned, New England to-day is a shambles. Last summer, in some regions, their numbers were reduced one half by the mercenary invaders. This year's warfare is expected to result in more extensive destruction. The government scientists who have engineered this most tremendous of all insect wars are confident that in a few years the moths will be under control. There may thereafter be occasional sporadic outbreaks of them, but they will no longer be a menace and a terror. No other nation has ever gathered an army of alien insects to protect its fields and for


The moths have been the most destructive insect scourges that ever visited our shores. They have caused damage to growing things that must be figured in hundreds of millions of dollars. Nothing to compare with this wide-spread destruc

and northern Africa, the native homes of moths abroad. If they appeared in great numbers in a certain part of the country one year, they would vanish the next.

The gipsy-moth really arrived in the United States as early as 1869. Professor Leopold Trouvelot, an astronomer connected with Harvard University, had a hobby for silkworms. He imported spinning caterpillars from all over the world, and studied them at his home in Medford, Massachusetts. Among his specimens were some egg clusters of the gipsy-moth, which he kept on a shrub under a net in his dooryard. One night a sudden gale, undoubtedly the costliest storm New England ever experienced, tore the net and scattered the insects. The frantic professor dashed about the neighborhood destroying all the insects he could find. He wrote warning letters to the entomological journals. But the mischief was done. Not until twenty years later, however, were the moths noticed. Then they appeared in enormous swarms. A few years after this the brown-tailed moth, which had come in on nursery stock imported from France, made its appearance in Somerville, Massachusetts. During recent years the Government and the New England States have been spending half a million dollars annually to fight the moths.

But though hundreds of persons and elaborate apparatus were employed to keep the moths in check, they increased by millions, and year by year the situation grew worse. They spread over the greater part of New England and threatened the country.

A study of moths in foreign countries revealed that their existence was made precarious by scores of varieties of other insects that preyed upon them. For these winged parasites the moths were at once food and drink and home, and for the young grubs they were the nurse and the

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stages of development were soon being received from many lands at the combined, nursery and barracks established by the Government at Melrose Highlands, Massachusetts, for the rearing and study of the insect army.

Of course the transportation of this sort of live stock was new, and the mortality en route was often tremendous. The Oriental specimens traveled six thousand miles to get here. Most of them had to be carried in cold storage from the time they were gathered in the fields in Japan until they reached the laboratory in Massachusetts. Otherwise they grew to maturity, and either died or escaped before they reached our shores. The first results were discouraging, but the workers persisted. Since 1906, when the first big shipments arrived, 300,000 boxes and cases of moths and parasites have been received.



without the parasites, and, freed from their natural enemies, they had become a plague.

The government scientists therefore went abroad on a huge insect hunt. They searched Europe from end to end, wherever moths were to be found. One man journeyed across the Pacific to Japan. Entomologists all over the world were enlisted in the fight to save the forests and crops of the United States from destruction. As a result of this strange hunt, parasites and parasitized moths in all

The reception of the shipments was merely the beginning of Uncle Sam's troubles. The entomologists at Melrose Highlands soon found themselves envying the comparative leisure of the Old Woman Who Lived in a Shoe. Their insect children were appearing by the hundreds of thousands. Each package of specimens received was a Pandora's box of winged troubles. sorts of strange worms and flies and grubs were popping out of the mass of material dumped into the laboratories. There were insects that attacked the moths, and insects that ate one another, and strange insects, with no apparent mission in life, that no one had ever noticed before. They had to be sorted and watched. Before any of them could be set at liberty, the scientists must determine whether they would really prove effective fighters against the pests. No real study had ever been made of moth


parasites, and the efficient ones bore no label.

The diminutiveness of the little warriors was an additional handicap. Some of them were too small to be discerned by the naked eye.

Sorting and examining hundreds of thousands of gipsy- and brown-tailed eggs were only details of the search for parasites. Sorting over half a million hens' eggs would scarcely be a light task. The eggs of the brown-tailed moth, at their largest diameter, are somewhat smaller than the period that ends this. But small as


they are, the microscope has revealed ten minute fly parasites grown to maturity within a single brown-tailed egg! The mother fly had deposited her own eggs within that little dot of albumen, and her offspring had found sufficient nourishment within to bring them to full flyhood. There they were, when the glass caught them, with a full tally of legs and wings and bodily organs, ready to burst into the world for a brief three weeks of active life.

dent for their confidence. As far back as the eighties, when the fluted-scale insect was killing the orange- and lemon-groves in California, a highly effective ladybird had been imported from Australia to fight the scale. When colonies of the ladybirds were liberated, they immediately pounced upon the nearest scale insects and de


From a photograph


The female gipsy-moth is so heavy that she flies with difficulty. Her brown-tailed sister can negotiate great distances.

Thirty varieties of flies were gathered from Europe and Asia, and within the laboratory they increased very rapidly. There was one midget, a Japanese specimen, that for three years defied all efforts at importation by escaping or dying on the way. Finally, in 1909, eleven live specimens survived the voyage. From these eleven have been produced nine generations in seven months, at the end of which time a census was taken, and the surviving family was found to number 1,300,000 flies. There was decidedly no race suicide there.

By this time a huge fighting force hundreds of thousands of flies-was being placed in the field, and the scientists waited confidently for results. They had a prece

voured them, and so completely did they do their work that the California orchards were cleared of the pest within two years. To this day the California State Board of Horticulture maintains a barracks of these doughty amazons in Sacramento, and whenever the scale appears, several regiments of the ladybirds are rushed to the infected orchards, and make short work of the pest.

The moth flies made no attempt to emulate the ladybirds. As soon as they

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were released, they mysteriously vanished. The neighborhoods in which they were colonized were searched over and again, but no trace of them was found. The scientists became very pessimistic about those flies. The first of them had been set free in 1907. By 1910 even the most enthusiastic entomologists were ready to admit failure. Perhaps the flies had been unable to withstand the rigors of a New England winter in the open. Perhaps they were homesick for Europe and Japan, and preferred starvation to life in a strange land. The non-scientific government of Massachusetts, which was sharing with the National Government the expenses of the warfare against the moths, began to grumble about time and money spent on parasites that did not parasitize. And the overworked scientists really had very little defense.

But a surprise awaited every one. In 1911 regiments of the fly armies were found in remote parts of New England valiantly slaying the moths. Last summer it was determined that they had increased to myriads, and some varieties had spread over ten thousand square miles.

The reason they had not been discovered at first was because each and every one of the flies was inspired with a passion for exercise. Their business in life was to attack and devour moths. But they had no appetite for moths in the immediate neighborhood. Their instinct gave the strange little creatures an appetite for moths a mile or more away!

One of the most effective flies is the diminutive Japanese warrior, who, after his arrival, increased his numbers from eleven to 1,300,000 in seven months. He is of the Schedius genus and has been christened Kuvanae in honor of Professor S. I. Kuwana of the Imperial Agricultural Station at Tokio, who sent us the first specimens received alive.

This Japanese midget prefers its caterpillars served in the egg. The Hon. Mrs. Schedius deposits her honorable egg within the body of the unhatched gipsy-moth caterpillar. Within a few days the honorable egg has become the honorable larva, a tiny grub with a passion for food. No child in a fairy-tale who awoke in a gingerbread house was ever better provided for than this infant. It is entirely

surrounded by breakfast. And it proceeds to eat and eat and eat until nothing is left of that embryo caterpillar except the head and claws and hair. By this time the honorable grub is ready to emerge and develop into the honorable fly and establish a new little honorable family of fifty or a hundred in other gipsy-moth eggs.

But life is not always a fairy feast for the Schedius grub. Sometimes it has no sooner waxed fat with feasting than another sort of fly mother will come along and deposit her eggs within the Schedius. The new-comer will soon begin feasting on the gorged grub, which of course has no more chance than the original caterpillar inhabitant of the moth egg. There are several varieties of insects which prey indiscriminately upon the gipsy-moth or on one another, and according to the scientists, four or more insects may successively devour one another internally within a single moth egg in the fields in Japan. Of course great care was taken to release no secondary parasites here.

The microscope revealed a curious triple tragedy of this character, in which Schedius secured a terrible revenge upon another insect which commonly preys upon it. The larva of this midge, which the scientists call Anastatus, had established itself within the unhatched gipsy caterpillar, had eaten the entire contents of the shell, and, after its indolent fashion, had settled down to ten months of

sleep before emerging into the world. Three Schedius mothers, in rapid succession, had flown up and deposited eggs within the torpid body of the fat intruder. When the microscope revealed them, the three Schedius grubs were developing rapidly within the Anastatus. Having destroyed him, they were ready to engage in a further struggle to determine which one of them would devour the others and live to flyhood. For it is the law of the clan that only one shall emerge alive. Whether the tiny grubs of the same family actually engage in a struggle for supremacy, or whether the hardest eater devours his kinsmen, who yield their bodies passively to superior strength and appetite, science has not determined. A battle that takes place within an area much smaller than a pinhead is not easy to observe.

Another Japanese fly inflicts upon the immature moths a death of exquisite torture. It deposits its eggs within the body of the full-grown moth caterpillar. The eggs hatch rapidly, and the larvæ feast for two or three weeks before they force their way out through the skin of the still-living caterpillar. A full-grown caterpillar may harbor a hundred or more of these. For its protection during further development, each of the newly emerged worms immediately spins a small white cocoon. And the caterpillar, unable to leave the spot, dies slowly, "surrounded by and seeming to brood over the cocoons."

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