Hawk Moth , the proper name of the second or crepuscular division of the order lepidoptera, corresponding to the old genus sphinx (Linn.), most conveniently divided into the sections of sphinxes, aegerians, and glaucopidians. For the characters of the order both in the perfect and immature state, see Butterfly, and Caterpillar. The hawk moths have the antennae fusiform or thickest in the middle, and generally hooked at the tip; the comparatively narrow wings are retained in a horizontal or slightly inclined position by a bristle or bunch of stiff hairs on the shoulder of each hind wing, which is received by a hook on the under side of each fore wing, the upper ones covering the lower; there are two pairs of spurs on the hind legs. Most of these insects fly in the morning and evening twilight, though a few appear by day. Linnaeus gave the name of sphinx to this group from a fancied resemblance of some of their caterpillars, when at rest, to the Egyptian figure; supporting themselves on the posterior pairs of legs, they raise the fore part of the body, and remain fixed in this position for hours at a time.
The adult sphinxes are generally called humming-bird moths from the noise they make when flying, and hawk moths from their hovering and powerful flight; the body is thick and robust, and the strong wings long, narrow, and pointed; with their very long tongues they obtain honey from flowers while on the wing; many are of such size, and have such brilliant colors, that they might readily be taken for humming birds. Some of the aegerians also fly by day; though their flight is swift, it is not prolonged, and they generally alight while feeding; they much resemble bees and wasps; they have a tuft at the end of the body which can be extended like a fan. The glaucopidians, so named from the bluish color of the eyes in some of the species, have the antennas feathered on each side; they fly mostly by day, and alight to take their food. The large green caterpillar, with a horn on the top of the last segment, commonly called potato worm, is a good example of the larva of the sphinx moth. In this division all have 16 legs, in pairs beneath the first to third and sixth to tenth or last segments of the body; and all, except the aegerians and glaucopidians, have a horn or tubercle on the top of the last segment. The sphinx caterpillars devour the leaves of plants on which they are found.
The caterpillars of the aegerians are called borers, in common with the larva) of other orders of insects, from their living concealed within the stems or roots of plants, and feeding upon their interior substance; they are soft, whitish, and slightly downy; they make a cocoon with bits of wood cemented by gummy matter, within which they are transformed into chrysalids; these are of a shining bay color, having the edges of the abdominal segments armed with rows of short teeth, by means of which they work out of the cocoon and out of the hole in the wood.
Hawk Moth (Sphinx quinquemaculatus).
Larva and Chrysalis of Sphinx quinquemaculatus.
The caterpillars of the glaucopidians are slender, with a few scattered hairs or tufts; they eat the leaves of plants, and undergo transformation in cocoons of coarse silk; the chrysalids are round at one end, tapering at the other, without teeth on the surface; they much resemble the nocturnal moths. - The potato worm, or larva of the sphinx quinquemaculatus, with oblique whitish stripes on the sides, grows to a length of 3 or 4 in. and the thickness of the finger; it attains its full size toward the end of August, and often injures the plant by devouring the leaves; crawling into the ground, it remains a chrysalis during the winter, and in the following summer comes out a large moth, measuring 5 in. across the wings; the color is gray, with blackish lines and bands, and five round orange spots encircled with black on each side of the body; the tongue, which when not in use is coiled like a watch spring, may be unrolled to a length of 5 or 0 in. The elm is infested with a pale green caterpillar, about 3 1/2 in. long, with seven oblique white lines on each side, a row of little notches on the back, and four short notched horns on the shoulders; this is the larva of a sphinx (ceratomia quadricornis, Harris;, and sometimes commits considerable mischief during July and August; these larvae pass the winter in the earth, and come out in the following June large moths, with an expanse of wings of nearly 5 in.; the color is light brown, varied with darker and with white, with five longitudinal dark brown lines on the hind part of the body.
This caterpillar is easily caught in the morning during the season of maturity. Grape and other vines are attacked by the larvae of the satellitia and achemon hawk moths, the moth of the former being of a light olive color and expanding 4 or 5 in., and of the latter reddish ash, with brown patches on the thorax and anterior wings, and expanding 3 or 4 in. For details on other sphinxes injurious to vegetation, see the work of Dr. T. W. Harris, "On Insects Injurious to Vegetation." The sphinx caterpillars, being of large size and full of juices, are commonly chosen by the ichneumon flies as the nidus in which to deposit their eggs, the larvae from which, feeding on the substance of the caterpillar, and frequently spinning their cocoons in great numbers on the outside, so reduce it that the metamorphoses do not take place; multitudes are destroyed in this way. - Ash trees and cucurbitaccous vines suffer much from the boring larvae of aegerians; the former from the trochilium dentatum (Harris), of a brown color, with yellow markings, expanding about 1 1/2 in.; the latter from the oegeria cu-curbitoe (Harris), with an orange-colored body spotted with black, and with its fore wings expanding about 1 1/2 in.
Peach and cherry trees throughout the United States have of late years been infested with a naked whitish borer, the oegeria [T.] exitiosa (Say); the perfect insect is a slender dark blue moth, the males being much the smaller, and differing considerably in marking from the females. For an account of these insects, and the best ways of preventing their ravages, see Dr. Harris's papers in vols. v. and ix. of the " New England Farmer." - The glaucopidian moth (procris Americana) is in some years very injurious to vines, stripping off the leaves in midsummer. Its wings are very narrow, expanding about an inch; the color is blue black, with a saffron collar; the caterpillars are yellowish, with black velvety tufts on each ring, and a few hairs on the end of the body. They are about half an inch long, gregarious, and rather sluggish in their motions; in the southern states several broods are hatched in a season. For a full account see "Hovey's Magazine" for June, 1844. - Many species of all these sections are found in Europe, where their habits have been carefully observed.