THE UTILITY OF ENTOMOLOGY
All the forces of nature are interdependent. Many plants would not bear seeds or fruit were it not for the activity of insects, which cause the pollen to be deposited upon the pistil and the seed-vessel to be fertilized. Attempts were made many years ago to grow clover in Australia, but the clover did not make seed. All the seed required for planting had to be imported at much expense from Europe. It was finally ascertained that the reason why the clover failed to make seed was because throughout Australia there were no bumblebees. Bumblebees were introduced, and now clover grows luxuriantly in Australia, making seed abundantly; and Australian meats, carried in the cold-storage rooms of great ocean steamers, are used to feed the people of Manila, Hong-Kong, Yokohama, and even London.
A few years ago the orange-groves in southern California became infested with a scale-insect, which threatened to ruin them and to bring orange-growing in that part of the land to an unprofitable end. The matter received the careful attention of the chief entomologist of the United States Department of Agriculture, the lamented Professor C.V. Riley. In the course of the studies which he and his associates prosecuted, it was ascertained that the same scale-insect which was ruining the orange-groves of California is found in the orange-groves of Queensland, but that in Queensland this insect did comparatively small injury to the trees. Investigation disclosed the fact that in Queensland the scale-insect was kept down by the ravages of a parasitic insect which preyed upon it. This parasite, by order of the chief entomologist, was immediately imported, in considerable numbers, into southern California, and let loose among the orange-groves. The result has been most beneficial.
These are two illustrations, from among hundreds which might be cited, of the very practical value of entomological knowledge.
The annual loss suffered by agricultural communities through ignorance of entomological facts is very great. Every plant has its insect enemy, or, more correctly, its insect lover, which feeds upon it, delights in its luxuriance, but makes short work, it may be of leaves, it may be of flowers, it may be of fruit. It has been estimated that every known species of plant has five or six species of insects which habitually feed upon it. Where the plant is one that is valuable to man and is grown for his use, the horticulturist or the farmer finds himself confronted, presently, by the ravages of these creatures, and unless he has correct information as to the best manner in which to combat them, he is likely to suffer losses of a serious character. We all have read of the havoc wrought by the Kansas locust, or grasshopper, and of the ruin brought about by insects of the same class in Asia and in Africa. We all have heard of the Hessian fly, of the weevil, and of the army-worm. The legislature of Massachusetts has in recent years been spending hundreds of thousands of dollars in the attempt to exterminate the gipsy-moth. The caterpillar of the cabbage-butterfly ruins every year material enough to supply sauer-kraut to half of the people. The codling-moth, the little pinkish caterpillar of which worms its way through apples, is estimated to destroy five millions of dollars' worth of apples every year within the limits of the United States. And what shall we say of the potato-bug, that prettily striped beetle, which, starting from the far West, has taken possession of the potato-fields of the continent, and for the extermination of which there is annually spent, by the agricultural communities of the United States, several millions of dollars in labor and in poisons?
A few facts like these serve to show that the study of entomology is not a study which deserves to be placed in the category of useless pursuits. Viewed merely from a utilitarian standpoint, this study is one of the most important, far outranking, in its actual value to communities, the study of many branches of zoölogical science which some people affect to regard as of a higher order.
The legislature of Pennsylvania acted wisely in passing a law which demands that in every high school established within the State there shall be at least one teacher capable of giving instruction in botany and in entomology. The importance of entomology, while not perceived by the masses as yet, has been recognized by almost all the legislatures of the States; and not only the general government of the United States, but the governments of the individual commonwealths, are at the present time employing a number of carefully trained men, whose business is to ascertain the facts and instruct the people as to the best manner in which to ward off the attacks of the insect swarms, which are respecters neither of size nor beauty in the vegetable world, attacking alike the majestic oak and the lowliest mosses.
Genus LYCÆNA, Fabricius
(The Blues)