Locust, a saltatory orthopterous insect, of the family locustadce, and the genera acrydium, locusta, captenus, and others. The locusts are characterized by roofed wing covers, short antennae not tapering at the end, three-jointed feet, and absence of projecting ovipositor. The extremity of the body in the female is provided with four short wedge-shaped pieces, arranged in pairs, and moving up and down like double nippers; these are forced into the ground, enlarging the hole as they are opened and withdrawn until it is deep and large enough to receive the eggs. The males make a loud noise by rubbing their hind legs across the projecting veins of the wing covers, like playing upon a violin, the sound being intensified by a sonorous cavity in the first abdominal segment. The hind legs are very powerful, enabling them to leap much better than the grasshoppers; their strong and narrow wings give them the power of rapid and long continued flight, accompanied by a loud whizzing noise, compared in their immense swarms to the rushing of a whirlwind, the rattling of chariots, and the crackling of burning stubble.
The Carolina locust, about 1 1/2 in. long with an expanse of wings of about 3 in., is pale yellowish brown, with dusky spots, and black wings broadly margined with yellow; this species, well known for its sharp noise during the hottest days of summer, is found abundantly by the roadside, flying before the traveller to a considerable distance; it prefers warm and dry places, but is sometimes seen near salt marshes in company with the red-legged species; the eggs, deposited in the ground in autumn, are hatched in the folio-wing spring. In the genus tetrix, or grouse-locusts, Dr. Harris describes seven species; they are found in the hottest places, and leap to an astonishing distance; they may be known by their small size, and their keeled thorax resembling a reversed boat. - The celebrated locust of the East (locusta migratoria, Linn.; placed in the genus acrydium by Latreille) is about 2 1/2 in. long, of a greenish color obscurely spotted, with pale brown wing covers marked with black. Its special habitat is western Asia, northern Africa, and southern Europe, whence it has spread even to England and northern Europe. It is destructive in all its forms, in the larval, nymph, and perfect conditions, feeding voraciously on plants.
It will be sufficient here to allude to the devastations committed by locusts, as most books of eastern travel describe the steady and irresistible progress of their vast swarms, destroying every trace of vegetation in the districts visited by them. Their numbers are so incredible that rivers have been blocked and many square miles covered by them, the stench of their decaying bodies infecting the air for hundreds of miles. Messrs. Kirby and Spence mention an army of locusts which ravaged the Mahratta country, extending in a column 500 miles long, and so compact that it obscured the sun like an eclipse; this, however, was another species, of a red color, which produced an additional bloody hue as they stripped the trees of their foliage. Many are the allu-sions in the Old Testament to the flight of these insects, and the prophet Joel (ch. ii.) gives a magnificent description of their appearance. The locusts were considered by the Hebrews and other eastern nations, and still are by the Arabs, as the avenging armies of the Deity; the latter assert that a statement to this effect exists in good Arabic on the wings of the insect; they do not occur in large swarms every year, but only every fourth or fifth season, and generally toward the end of May. Locusts are used as food in the countries where they abound; the legs and wings being pulled off, the bodies are fried in oil, and are considered a delicacy; they are sometimes dried in the sun, pounded up, and used as a flour for making bread.
In many towns in Arabia there are shops where locusts are sold by measure. Other species are common in Africa, where they are also used as food. Gordon dimming describes these insects in Africa as coming on like a snow storm, flying slowly and steadily about 100 yards from the ground; the air was darkened by their masses, and the plain upon which he stood became densely covered with them; as far as the eye could reach in every direction, they stretched in one unbroken cloud, and more than an hour elapsed before their devastating legions swept by; they form in Africa food for man, cattle, car-nivora, and birds. Locusts have also committed considerable ravages in America; most of the devastation popularly attributed to grasshoppers really belongs to locusts, and most often to the red-legged species (C. femur-ru-urum, Burm.); they have proved specially destructive to the grass of salt meadows, clover, corn, and vegetables, until arrested by the early frosts; the hay crop is sometimes so much tainted by their decaying bodies that cattle refuse to eat it.
Toward the middle of the 18th century these insects were so abundant in northern New England that days of fasting and prayer were appointed on account of the wide-spread calamity; and of late years they have been very destructive in the newly settled western states and territories. The C. spretus, popularly but erroneously called a "grasshopper," has this year (1874) committed terrible ravages in Minnesota and other western states, destroying about one tenth of the grain crop. - Various methods have been resorted to to check the ravages of locusts. A bounty has been given for their eggs; they are devoured by insectivorous mammals and birds, especially domestic fowls; the sand wasp preys upon them; intestinal worms (gordius) and red mites (ocypete) feed upon their juices and finally kill them; winds sweep them into the sea, and immense numbers are drowned by the high tides which inundate the marshes. The natural causes of destruction, after all, are more to be relied on than the occasional and isolated attempts of the farmer, who here rarely suffers in comparison with those of eastern nations. - The harvest fly and some species of grasshoppers are often erroneously called locusts in the United States. (See Grasshop-per, and Harvest Fly.)
Eastern Locust (Locusta migratoria).
Locust (Robinia), a North American genus of trees and shrubs, of the order leguminosae; they have stipular spines, flat seeds in many-seeded, compressed pods, preceded by showy white or rose-colored flowers, in simple, usually pendent, axillary racemes. The common locust tree (R. pseudacacia) grows in some districts to a great size, in the southwest reaching 70 or 80 ft. with a diameter of 4 ft.; it has a straight, lofty stem, covered with a thick, deeply and irregularly furrowed bark, and with strong, rude branches, ending in slender, virgate spray, which is clothed in summer with a soft velvety foliage, consisting of unequally pinnate leaves, often seen bright and clean by the dusty roadsides in the heat of the season, and then refreshingly beautiful; or earlier, with a profusion of fragrant, clustered, pendent blossoms. The locust tree loves the fertile soils westward of the Alleghany mountains, and extends thence as far as Arkansas; but it is not indigenous north of Pennsylvania, nor to be found wild near the sea-coast in the southern states. When growing upon thin soils, it is observed that it greatly improves them if unmolested, probably by the rapidity with which its small leaflets decay and form a natural compost or surface soil, bringing in a grassy sod.
The locust plantations upon Long Island have been found to materially improve the soil, and at the same time afford a profitable crop of timber. The tree throws up numerous suckers, especially if the roots are wounded by the plough, and on this account it is objectionable in some situations; the suckers are sometimes used for making plantations, but the trees are never so shapely as those raised from seeds; it grows readily from seeds, which may be sown as soon as they are ripe in the fall; if kept until spring the seeds must be scalded to insure germination. The great enemy to the successful cultivation of the locust is the borer, the larva of clytus robiniae, a beautiful gold and black beetle which is found in great abundance on the goldenrods and other flowers in September, during their pairing season; the female then deposits her eggs upon the bark of the tree, and the young larvae soon make their way to the interior, where from their great numbers they cause much damage; the larva perfects itself in one year. About 20 years ago this insect completely devastated the locusts in some of the western states. The only remedy that has been suggested is to plant in large groves, as the insect naturally seeks the trees upon the borders of a plantation.
The free and unrestrained growth of the locust tree is very rapid, and its stem increases in magnitude to such a degree as to make valuable timber. It is not uncommon for young plants to attain a growth of 8 or 10 ft. in a single summer, and one sprout from a young stump of a yellow locust tree grew 16 1/2 ft. The wood of the tree is yellowish, but the color varies, and lumbermen distinguish the white, yellow, and black locusts, as the wood is light or dark in color; whether these peculiarities are due to soil, or belong to distinct races or " strains," is not well ascertained; the darkest colored wood is considered the most durable. For certain uses in ship building the wood of the locust is preferable to any other timber. Where strength or durability in the material is required, its value is acknowledged. It makes excellent posts for fences and gates, sleepers for foundations, and ties for railroads; the writer has seen locust fence posts taken up that were known to have been in the ground for 60 years; they were so sound that they were set again; and mill cogs and similar articles in constant wear are constructed of it.
A tree so beautiful, so rapid in increase, so valuable in economic uses, recommends itself for artificial cultivation upon acres of land otherwise almost valueless and to be found on every extensive farm. The locust tree was carried to Europe in the time of Henry IV. of France, and was named Robinia in honor of Robin, father and son, who first introduced and cultivated it. The locust has produced some remarkable varieties from the seed,, and European catalogues enumerate more than 20 named sorts in which there is some striking departure from the normal form; one of the finest of these is one named in honor of Prof. Decaisne (R. pseudacacia, var. Decaisneana), which has delicate pink flowers, and blooms almost all the season. - A southern species, known as the clammy locust (R. viscosa), occurs upon the mountains of Virginia and southward; it is from 20 to 40 ft. high, the petioles, peduncles, and young wood covered with a viscid pubescence. The flowers are white tinged with pink; the seed pod is glandular-pubescent, three- to four-seeded. This species is cultivated at the north for ornament. One other species (R. hispida), called rose acacia and also moss locust, is only a straggling shrub from 3 to 5 ft. high, but its flowers are very large and of a deep rosy color.
The branches, stalks, and pods are bristly. It is frequently cultivated, but as it has a disposition to throw up from its roots numerous suckers, it is much better to graft it into the common locust; and when thus set on a tall young stock of that species, the effect is exceedingly beautiful; it is also sometimes trained to a trellis. (See Honey Locust.)
Moss Locust (Robinia hispida).