government grant and the sale of its publications. The Brooklyn Entomological Society was organized in 1872 and in 1888, while retaining a corporate existence, became merged in the Brooklyn Institute, forming the department of entomology of that institution. It published seven volumes of a 'Bulletin' and six volumes of Entomologica Americana.) The Cambridge Entomological Club, founded at Cambridge, Mass., in 1874, publishes Psyche, a quarterly originally devoted largely to bibliographical and biological entomology. The same year The Entomological Club of the American Association for the Advancement of Science was formed. In 1884 The Entomological Society of Washington was organized, publishing 'Proceedings. The Association of Economic Entomologists, as has previously been mentioned, was established in 1889. Its 'Proceedings are published in the general series of bulletins of the Division of Entomology of the United States Department of Agriculture. In 1881 The New York Entomological Club began the publication of 'Papilio,' but at the end of its 4th volume its members joined the Brooklyn Entomological Society. In 1892, however, another society was organized in New York as The New York Entomological Society. It was incorporated in 1899.

In addition to these principal publishing entomological associations there are several other entomological sections of larger scientific_societies in Canada and in the United States. There are also local clubs or societies in various sections, for example, in Newark, N. J.; at Williamsburg, N. Y.; at Chicago, Pittsburgh and in San Francisco, the home of the California Entomological Society..

There are many foreign societies, nearly all of the largest cities of Europe supporting one or more, usually holding titles significant of an entire nation, for example, there are entomological societies of Belgium, France, Switzerland, Russia, Italy and Germany, and others representing the cities of London, Berlin, Vienna and Stockholm. See also AMERICAN ENTOMOLOGICAL SOCIETY and consult Skinner, H. (ed.), 'Entomologists' Directory, containing the names, addresses, special departments of study, etc., of those interested in the study of insect life in the United States and Canada) (Philadelphia 1904).

ENTOMOLOGY, the science which deals with insects. See INSECTS.

ENTOMOLOGY, Economic. Attacks by insects upon useful plants doubtless began with the first cultivation of plants; but it was not until the end of the 18th century that any means for mitigating their ravages were employed beyond hand methods and other purely mechanical measures. A few crude efforts were made among the ancient farmers and fruit-raisers on the shores of the Mediterranean toward the suppression of insect pests and Pliny even advised the use of white hellebore, one of the modern insecticides; but it was at about the middle of the 19th century that insecticides (q.v.) or insect poisons began to be generally adopted, and the migration of the Colorado potato beetle from its native home in the Rocky Mountain region to the potato fields of the East was the indirect means of the employment of arsenical preparations as a means of destroy

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ing insects; so that this insect, while an apparent curse, has proved, indirectly, of the greatest value to the agricultural community at large. Prior to the use of Paris green, which appears to have first been applied to this potato pest in Michigan in 1867, knocking the beetles from the infested plants into a pan of water was the only method of treatment and was used for many other insects as well. The discovery of the value of this poison as a remedy for the codling moth was made in 1878, by Prof. A. J. Cook, who used Paris green as a remedy for canker-worms and found that the trees treated with it were free from codling moth. To Professor Cook also is probably due the first use of kerosene mixed with soap, although the kerosene emulsion, which is now a standard remedy for all sucking insects, was the joint product of Messrs. Barnard, Hubbard and Riley, and first used in 1877. White arsenic was employed as an insecticide as early as 1871 and London purple was put to practical use in the destruction of the cotton worm in 1878. London purple has since been displaced by various other insecticides, as it has proved inferior to Paris green, which, in turn, has been replaced by arsenate of lead, because the latter, while poisoning the insects, does not scald or otherwise injure the plants. In the same manner the discovery of Paris green as a remedy for the Colorado potato beetle was made through the migrations of this insect, the rayages of the cotton cushion scale (Icerya purchasi) of the orange orchards of California led to experiments conducted by Mr. D. W. Coquillett, of the United States Department of Agriculture, in 1886, to the finding of hydrocyanic-acid gas as the best medium for extirpation of scale insects (q.v.), and to its general use in fumigation for all insects which can be treated with it. In 1895 Messrs. A. F. Woods and P. H. Dorsett, also of the Department of Agriculture, began experiments which led to the adoption of a perfected system of fumigation with the same gas of plants grown under glass and injured by scale and other insects.

Our best remedies for insects, then, arsenical mixtures and kerosene emulsion and other preparations, and hydrocyanic-acid gas, are the product of American research. The bisulphide of carbon as an insecticide, however, though the discovery of a foreigner, has doubtless received greater attention in our country than elsewhere. It was first employed by M. Doyère, as early as 1856, as a remedy for weevils in stored grain, which is still its principal use; but its cost when first employed was so excessive as to preclude its general employment on a large scale. Subsequently a high grade of this chemical, known as "fuma-bisulphide," was made for sale at 10 cents a pound. It supplements the use of hydrocyanic-acid gas in that the former is used for the fumigation of plants above ground, while the latter destroys insects affecting the root-system. Both gases are used for the treatment of indoor insects in granaries and mills and in dwellings and warehouses. Although these are the main insecticides, there are others, nearly all of which owe their discovery and perfection to economic workers in America. They include pyrethrum, better known as Buhach, Persian and Dalmatian insect powders, the extensive use of which has resulted in the establishment of a considerable

industry in the growing of the principal plants which produce these powders (Pyrethrum cinerariæ folium and Pyrethrum roseum); and whale-oil and fish-oil soaps, originally used against the hop aphis in 1886, and later against scales.

In more recent years lime-sulphur combinations have been used as washes and sprays against scales and other sucking insects with good results. Still more recently nicotine sulphate standardized at 40 per cent purity has come into general use as a contact insecticide for the same class of insects, and is now a standard remedy in combination with soap for the control of aphides or plant-lice, the on on and pear thrips and related species, leafhoppers, plant-bugs and many others. Prior to this time tobacco preparations were used but with indifferent success except on a restricted number of insect pests.

Quassiin is the subject of investigation as a contact insecticide. Of arsenical poisons arsenite of zinc and arsenate of calcium are effective but not superior to arsenate of lead. Adhesives, such as whale-oil (fish-oil) and other soaps, are also in general use under the name of "stickers." Repellents, to prevent such insects as the parent flies of root-maggots from depositing their eggs, are being successfully employed and in some cases odorous substances are being used to attract insects from their natural foods where they can be destroyed.

As fumigants, hydrocyanic-acid gas generated from sodium cyanid is in general use for the destruction of mill and granary insects, greenhouse and household pests. Carbon tetrachloride and para-dichlorobenzene are excellent fumigants, but too costly for general use. Insects affecting stored products and pests in households may also be controlled by heat – an old remedy which is now employed in many mills and warehouses where steam-heating plants are installed.

During the early years of work in spraying for various insects the principal dependence was placed in American insecticide machinery, but after the invention of different forms of nozzles by M. Vermorel, of France, various other nozzles, pumps and other machinery were invented in America and have gone into general use.

An almost incredible number of spraying machines and appliances are being manufactured and constant improvements are being made adapted to special purposes.

Prevention of Insect Injuries by Farming Methods. It would be difficult to detail step by step the wonderful progress that has been made in means of subduing insects by simple farming methods which, as a rule, necessitate little or no extra labor or monetary outlay. Some of our principal pests, with which we cannot cope successfully by means of insecticides or by mechanical methods, may be controlled by the judicious use of ordinary methods of tillage. The seed, nursery or other stock for planting should be selected with a special view to securing immunity from attack by the insect most feared or most prevalent in the region where the crop is to be planted. By planting different immune varieties of wheat the ravages of the Hessian fly are reduced to a minimum. Certain forms of trees may be selected for planting for shade in some regions without danger of injury, because the insects

which elsewhere do greatest damage to them are not present. The selection of a suitable location on the farm for a crop should be made with the same end in view. Where injury is feared by an insect which does not travel freely, immunity can be secured by planting in that part of the farm where the insect is known not to exist. The prompt destruction of crop remnants and the pulling up and burning over of weeds and other rubbish is a preventive applicable to all crops. Another measure is the use of "trap crops." Thus part of an old crop may be left to attract insects which usually remain in the field after the crop is made; similar or more attractive plants may be grown for the protection of the main crop; or of early varieties of the same plants, as lures for the insects until the main crop can obtain a good start. On the lure plants the congregated insects must be destroyed by poisons or by fire. Trap crops are of considerable value in the treatment of several of the worst enemies of cucumbers, melons, squashes and similar vines. The stimulation of a plant by means of fertilizers and the maintenance of healthy, vigorous growth by cultivation, the suppression of diseases and the prevention of injury by insect pests other than those which it is specially designed to circumvent, are helpful aids. Crop rotation or the planting of alternate crops which are not injured by those insects which ravage the staples assists in the warfare; as also do fall and spring plowing, which, in proper combination, result in the destruction of nearly all forms of the many insects which pass one or more stages in the earth in hibernation. The use of water by irrigation or submersion, if practised at the right time, will result in the temporary extirpation of nearly all insects in the fields thus treated, particularly in cranberry bogs. The reclamation by drainage of land subject to more or less complete submersion, such as swampy tracts, river bottoms and the like, and the destruction of the weeds and other plants and the insect life which remain by burning over, are of great value in suppressing many pests. If, to the methods above outlined, we add the strict observance of timely harvesting of crops with a view to the prevention of further attack and the destruction of insects which might reproduce the following year; the utilization of natural enemies, such as parasitic and predaceous insects, poultry and live stock, to destroy the insects in the field after the crop is off; the systematic inspection of the farm for the first appearance of insect attack, and, finally, the co-operation of neighboring farmers having a community of interests in growing the same crops, there is comparatively little use for insecticides save in the case of insects such as grasshoppers and the caterpillars of moths and butterflies, which are strong fliers and cannot be successfully controlled by mechanical methods.

Economic Entomologists.- Dr. T. W. Harris is credited with having been the first economic entomologist of America, but in reality the honor is due to W. D. Peck, who began writing on iniurious insects late in the 18th century (1795-1819). His writings, however, are few, in comparison to those of Harris, whose labors began in 1831 and whose greatest work appeared in 1841, his classic treatise on 'Insects Injurious to Vegetation.' In the year