LOCUST. Caloptenus. Orthoptera. The great devastation produced by grasshoppem, as they are generally called, but which are really locusts, deserve more than a passing notice of these destructive insects. In every age of the vvorld they have scourged continental countries. In the United States their depredations have been confined to the trans-Mississippi regions, and hence, until the settlement of that country they have attracted but little notice. The late Dr. Walsh, and his since famous pupil and co-laborer, Dr. Riley, and Dr. Thomas, the pre sent State Entomologist of Illinois, and Dr. Packard, have spent much labor in investigating the history and habits of the American species, and the three latter gentlemen are now just finishing up this work, as members of the Entomological Commission, under a special act of thc Congress of the United States. In 1866, Dr. Walsh published the results of his previous investigations of the insect which has since com mitted such wide-spread havoc, and to which he gave the name of Caloptenus spretus, and the English name of hateful grasshopper. In pre senting this subject Dr. Walsh remarked that the eggs, which in the autumn of that year were deposited in the trans-Mississippi country, in countless myriads, would not hatch out that autumn, but would lie in the ground until the succeeding spring, and then hatch out, if the conditions for life were proper, and do vast injury. At the same time he distinctly foretold that the locusts developed from these eggs would have their generative functions so impaired by the difference in food, climate, density of air, temperature, moisture, etc., which they met in the lowland country, that they vvould become incapable of further propagating their species, and that they would then and there die out ; also that the species would never cross the Mississippi river. The first of these predictions were fully verified, and the second has so far been as fully correct. The United States Ento mologicalCommission has now been engaged some three years in their investigations of the locust, and have added much valuable information and suggestions to what was known before. From their reports published by the Government, we shall freely extract the principal points of general interest. The account of the visitations up to 1877 will be found in the table on the next page. The classification and nomenclature or characters of the species of our locusts are given as follows : When the popular name of a group of insects or other animals, that is generally accepted, cor responds somewhat closely in its application to the scientific division, it is not difficult to convey to the general reader a correct idea of the posi tion and characters of a given species by refer ence to and comparison with well-known species of that group. Unfortunately, in the present instance, not only is the opportunity for refer ence to well-known species wanting, but the popular names applied to species and groups are so confused and erroneous that their use is cal culated to convey incorrect ideas to unscientific readers. Even the name locust as formerly, and
yet very generally, applied in this country is incorrectly used, referring to an insect not even belonging to the same order as the locusts of oriental countries. The seventeen-year locust of North America is, in fact, not a locust in the true sense, but a species of Cicada, or harvest fly, belonginglo the order Hemiptera, which con tains only insects with a mouth prolonged into a horny, jointed tube formed for sucking the juices of the plants or animals on which they feed. On the contrary, the locusts of the Old World, to which the term was originally and correctly applied, are species of migratory grass hoppers belonging to the order Orthoptera, and are furnished with strong biting jaws or mandi bles. There are other very material differences between the two, but these will suffice to show that they are quite distinct. The very common name grasshopper has likewise been unfortunate in its use and application not only in a popular sense, but even by scientists, referring at one time to the true locusts or to the various species of the family to which they belong, and at another to species of a different family, which includes katydids. In fact, the term as gener a,lly used applies to most of the species of two different families of Orthoptera. In order, there fore to convey a correct idea of the destructive species now under consideration we are neces sarily compelled to fall back upon the scientific arrangement and characters of the family, sub divisions, and species. Commencing with the order, we will give briefly the characters of the various divisions and subdivisions leading to the genus Caloptenus, to which the Rocky mountain locust belongs, omitting those divisions and groups not represented in the United States, and referring only to those characters which are most easily recognized, and which apply specially to our acridian fauna. The order Orthaptera is distinguished from the other orders of the insect class chiefly by the following characters: Mouth furnished with mandibles or strong biting jaws; wings four (occasionally wanting,) upper pair coriaceous or parchment-like and flexible; under pair thin and membranous, folding lengthwise only in plaits like a fan ; transformations incom plete, being active in all stages after hatching from the egg. Although not as extensive as some other orders, it contains a large number of species which differ very materially in appear ance and characters, and are generally known in this country by the common names earwigs, cockroaches, devil's-horses, walldng-sticks, grass hoppers, and crickets. Each of these names, except the next to the last, represents a distinct family of the order, as given below: Earwigs Family I. Forficutadce.