COCKROACH, or ROACH. An orthopterous insect of the family Blattiffie, several species of which are household pests throughout the civil ized world. Those most common are (11 The Croton-bup. (Blatta Germaniea), so called from its noticeable in New York when Croton water was introduced, lint which is of foreign origin, and of eosmDpolitau range, having followed civilized man to all parts of the globe; it is of medium size, brown or yellowish, with wings, in the adult, extending beyond the abdo men. (2) The Oriental or proper cockroach (Pcriplaneta Oriculalis) is also a videly dis tributed pest, introduced from the East. Al though it is not at all related to the beetles (Coleoptera), its Rritish name 'black beetle' well describes its dark, shining, robust, appear ance; its wings are characteristically shorter than the abdomen. (3) The American cockroach (Periplaucta Americana) probably originated in tropical America, whence it long ago spread to most of the seaport cities of the world; it is large and reddish brown, with very long wings. (4) The Australian cockroach (Periplaueht Aus tralasia.), much like the American, but smaller. In addition to these, which frequent houses, bakeries, warehouses, and shipping, there are a large number of wood-cockroaches but rarely seen.
that they .serve as scavengers to a small degree, and are the enemies of bedbugs.
Consult: for extended illustrated accounts of species above mentioned, Alarlatt, Household I n scels (Department of Agrieulture, Washington. 1896; revised reprint, 19(12) ; for general account of the Blattidx, Saussure, .11clanyrs Orthopt(' rolortiques, fascicule ii. (I;eneva, 1578) : for structure. Ca rpenter, Insects: Their Structure and Life (London, 1899).
Poises. During the latter part of the Paleozoic era cockroaches seem to have been very ablindant, and to have formed the dominant feature of the insect life of that time. Their remains are present, though much less abun dantly, ill the Triassic rocks also, and some have been found in the Tertiary. The total number of fossil species is about 225, of which number 193 species are Paleozoic. and of these 133 are
American. The Paleozoic cockroaches are as a rule larger, and have broader bodies than do the modern species. Their wings are quite Roaches as a group prefer warm, moist places. They go abroad mainly at night, and thus often escape notice even where they are abundant; and their excessively flattened body permits them to creep into very narrow crevices—below base boards, in table-drawers, etc., where the eggs ('nits') are laid, surrounded by a peculiar `pod;' but they are often carried by the female until nearly ready to hatch. The new-born young have nearly the same shape as the adult, but arc wingless and pale in color. They are practically omnivorous, injuring all kinds of provisions, eating parts of books, blackened boots, and even the nails and eyelashes of sleeping children. The loss caused to provisions by their appetite is far surpassed by the remaining food being rendered unfit for human use, on account of the nauseous `roachy' odor noticed wherever they congregate in large numbers. Their only claim to credit is in the shales of the Coal 'Measures and Permian at several localities, such as Richmond. Ohio; Cassville, W. Va.; Mazon Creek, Ill.; and Com mentry, France. At a localities the larval forms (nymphs) have been found and described under the generic name Dipeltis. The cockroach wings of the Coal Aleasures are usually found in shales that are replete with the leaves of ferns. One of the commonest ferns is Neuroptcris, and the insect's wings so closely resemble the leaflets of this fern that the likeness has been remarked upon and explained as a case of protective mimicry, adopted by the insect to enable it to elude its pursuers by hiding among the fallen fern-leaves.
For a fall history of these insects, with recom mendations for their suppression as a pest. con sult: Howard and Ma Hatt, "Principal Household Tnsects of the United States," in States Ilepurt men t of Agriculture, Dirision of Entomol ugly Bulletin 4, new .cries (Washington, 1896) ; also itlaill and Denny, The Structure and Life History of the Cockroach (London, 1887).