Observations. This species differs from the X. macrocarpon of Decandolle, by having smaller fruits, without horns, and whose thorns are neither hooked nor hispid; by not having an angular stem, but a round, spotted one, and by its leaves being broader, and not serrate, &c. Nearly all those differences exist between it and the X. orientale of Asia, which has not yet been isolated from the X. macrocarpon. The X. edrinatum differs from this by having oval fruits, with aggregated, echinate, and hooked thorns; and the X. strumarium, by having cordate hirsute leaves, the fruits aggregated, with hooked thorns and horned tops. The X. spinosum, and X. fruticosum, ate so totally different that they need not be compared.
ZOOLOGY.
Art. XIII. Description of the Phalaena Devastator, (the Insect that produces the Cut-worm.
Art. XIII. Description of the Phalaena Devastator, (the Insect that produces the Cut-worm,) communicated for the American Journal of Science, &c. by Mr. John P. Brace, of Litchfield, Conn.
This moth, whose larva is one of our most destructive enemies, belongs to the Linnæan family noctua, in the genus phalaena. Its specific characters are as follow: Wings incumbent and horizontal, when at rest; body long and thin; thorax thick, but not crested; head small; eyes prominent and black; antennæ setacious, gradually lessening towards extremities, and slightly ciliated; palpi two, flat, broad in the middle, and very hairy; tongue rolled up between them, not very prominent; clypeus small, legs long, small and hairy; wings long as body; under wings shortest; colour a dark silvery gray, with transverse dotted bands of black on upper wings. The insect lays its eggs in the commencement of autumn, at the roots of trees and near the ground: they are hatched early in May. The habits of the cut-worm have been often and fully detailed. They eat almost all kinds of vegetables, preferring beans, cabbages, and corn. They continue in this state about four weeks; they then cast their skin and enter the pupa state, under ground. This is a crustaceous covering, fitted to the parts of the future insect. In this they continue for four weeks longer, and come out in the fly, or insect state, about the middle of July. All those chrysalids that I exposed to the sun, died; and all those that were kept cool under earth, produced an insect: hence I infer, that the heat of the sun will kill the chrysalids. If, then, the ground be ploughed about the first of July, many of those insects might be destroyed, and the destruction of the productions of the next year prevented; for the pupa is never more than a few inches under ground.