Latreille further divides the various groups as follows; and although English authors have made many changes, the alterations are of such doubtful utility that the original classification will be retained.
The first class is that of insects without wings, such as the thysanura, or those having a bushy tail, which are mandibulate. Parasites or lice, and fleas, both of which are suctional, the last having a metamorphose, but the first two not. All others have wings, but the second class includes those that have a hard covering or case, called an elytron, over their wings; the beetles, which have a horny wing cover and perfect metamorphose; the dermoptera, which have a horny wing cover but an imperfect metamorphose; the orthoptera, or straight-winged insects, their wings folding longitudinally, and having a leathery cover—all of which are mandibulate; and the hemiptera, which have the wings half leathery and half membranous, and the mouth suctorial, and in both of the latter the metamorphose is imperfect. In the third class the wings are naked and alike; it includes the neuroptera, or nerve-winged insects, in which the veins of the wings are like a net; the hymenoptera, the wings being membranous, and veined lengthwise—both families being mandibulate; the lepidoptera, or scale-winged insects, having delicate scales on the wings—this order is suctorial, and the entire three orders have four wings; the rhipiptera, which are mandibulate and have two balances or halteres before the wings which close like a fan, whence their name is derived, and the diptera, which have two halteres behind the wings—in these families there are only two wings.
The orthoptera include, as familiar examples, cockroaches, crickets, katydids, and grasshoppers; the neuroptera white ants, May-flies, caddis-flies, dragon-flies or devil’s darning needles, and hoodlbugs; the hymenoptera common ants, wasps and bees; the lepidoptera butterflies, moths, silk-worms, and humming-birds; the hemiptera plant lice, cochineals, and locusts; the diptera mosquitoes, house-flies, horse-flies, and bot-flies.
The order hemiptera is frequently divided into two, according as the wings are of a uniform texture, homoptera, or of a varied texture, heteroptera; the lepidoptera are divided into three classes—those that fly by day, and generally have the antennæ knobbed; those that fly in the twilight and have the antennæ thickened, and those that are nocturnal and have the antennæ slender. The English writers have transposed the families grillidæ and locustidæ to suit the popular translation of the Scriptures, and have introduced a separate order called trichoptera.
As they are principally minute objects, wise men wisely concluded the deficiency should be made up in length of name, and but one class appears under the weight of less than four syllables. The families composing these orders are almost innumerable, and only those that are allied to the subject in hand can even be mentioned. Amateur entomologists prefer the coleoptera for their beauty and variety, and collections of insects are mainly composed of brilliant, gaudy and wondrous beetles, varying in size from the giant, as large as the pretty fist of one of the reader’s little female acquaintances, to the pigmy that is hardly perceptible to the eye. There is the beautiful and useful lady-bird, the wonderful lightning-bug, the elephant beetle with trunk and tusks, the hercules with stout heavy limbs, the palm weevil, whose disgusting grubs are eaten as delicacies by the deluded people of St. Domingo, and many other dangerous looking fellows with long sharp snouts that are really harmless, and innocent looking fellows that are really dangerous. The fly-fisher, however, relies for his pleasure mainly upon his imitations of the neuroptera and diptera, and not so much upon the coleoptera.
The young of the insect tribe, when it issues from the shell in the shape of a worm, is known as the larva, although the larvæ of some butterflies are called caterpillars, and of certain flies maggots. When the larva begins its metamorphose it is named a pupa or chrysalis, and the covering with which it surrounds itself a pupa-case or cocoon. It then undergoes a wonderful change, becoming the full-formed insect or imago—the ugly worm, that a short time previous had surrounded itself with a silken cocoon, bursting its case and flying off a gay, attractive and resplendent butterfly. From crawling meanly over the ground or the foliage, leaving a slimy streak behind, or horrible with a greenish smooth body and clinging feet, or disgusting with innumerable bristles, it soars away, its gay plumage glittering in the sunlight as it flits from flower to flower, the envy and admiration of the human female sex. How much is there not in beauty!
Many insects live for years as worms, and but a few hours in their perfect state. The ephemeræ, so called from appearing in the morning and dying before night, often do not reach half that age, although if the sexes are separated they will sometimes attain the great age of several weeks. They may be regarded as sacrificing their lives for the tender passion. They cover our waters in Summer, warmed into existence by the sun’s rays, flitting in a graceful but inefficient way from place to place, or floating calmly upon the surface, dropping back into nonentity with the departing sunlight. They are sometimes, especially in the southern country, quite large, and include what among fishermen are known as the May flies.
In some classes the change from the larva is not so remarkable, the worm having much of the appearance, and many of the distinctive marks of the perfect fly, as for example the bee; in these the metamorphose is said to be imperfect. The eyes of insects are either compound, composed of numerous lenses, amounting in certain butterflies to thirty thousand, or simple, called stemmata, the latter alone being found in the larvæ, although in some of the beetles the larvæ have eyes in the head and tail both. They are often long in maturing; one species of locust, as is well known, remains seventeen years before coming to perfection, and many other families continue several years as larvæ. Some of the larvæ live in the earth, some in wood, and others under water; some hide themselves in a cocoon ere their metamorphose is effected, others build houses of stones or sticks, others have no protection; but all are wonderful. One swims upon the water, another walks upon its surface, a third crawls along at the bottom, although the majority live upon dry land. In defence they use a sting, simulate death, eject a poisonous liquid, or emit an offensive smell. The eggs mature in the running or stagnant water, in the ground, in the limbs of trees, in the foliage and stems, or in the fruit. Grasshoppers in the East, grubs among savages, snails among Frenchmen, ants among Brazilians, locusts among prophets, and, if all reports are true, certain minute parasites among Italians, have furnished pleasing and nutritious food.
But of all the marvels of insect life, that which is least consonant with nature and least credible to human understanding, is the fact that they appear spontaneously. “Why should a few drops of rain in a dusty road produce animalculæ never seen before? Why should a little permanent dirt originate two distinct parasites, according as
