The imported cabbage butterfly (Pieris rapae), recently introduced from Europe, is estimated by the Abbe Provatncher, a Canadian entomologist, to destroy annually two hundred and forty thousand dollars' worth of cabbages around Quebec. The Hessian fly, according to Dr. Fitch, destroyed fifteen million dollars' worth of wheat in New York State in one year (1854). The army worm of the North (Leucania unipuncta), which was so abundant in 1861, from New England to Kansas, was reported to have done damage that year in Eastern Massachusetts exceeding half a million of dollars. The joint worm (Isosoma hordei) alone sometimes cuts off whole fields of grain in Virginia and northward. The Colorado potato beetle is steadily moving eastward, now ravaging the fields in Indiana and Ohio, and only the forethought and ingenuity in devising means of checking its attacks, resulting from a thorough study of its habits, will deliver our wasted fields from its direful assaults. These are the injuries done by the more abundant kinds of insects injurious to crops. We should not forget that each fruit or shade tree, garden shrub or vegetable, has a host of insects peculiar to it, and which, year after year, renew their attacks. I could enumerate upwards of fifty species of insects which prey upon cereals and grass, and as many which infest our field crops. Some thirty well known species ravage our garden vegetables. There are nearly fifty species which attack the grape vine, and their number is rapidly increasing. About seventy-five species make their annual onset upon the apple tree, and nearly an equal number may be found upon the plum, pear, peach and cherry. Among our shade trees, over fifty species infest the oak; twenty-five the elm; seventy-five the walnut, and over one hundred species of insects prey upon the pine. Indeed, we may reasonably calculate the annual loss in our country alone, from noxious animals and the lower forms of plants, such as rust, smut and mildew, as (at a low estimate) not far from five hundred million dollars annually. Of this amount, at least one-tenth, or fifty million dollars, could probably be saved by human exertions.