BLATTA, the cock-roach, in natural history, a genus of insects of the order Hemiptera. The 4eneric characters are, head inflected ; antennx setaceous ; wings flat, subcoriaceous ; thorax flattish, orbicular, margined ; feet formed for running ; hornlets two over the tail. The insects of this genus, and their larve, wan der about by night, and secrete themselves by day. They are fond of warmth, and haunt houses, devouring meal, and what ever provisions they can get at : they run with great celerity, and are destroy ed by the fumes of charcoal. In hot cli mates they are a great pest to society, by not only devouring whatever they can get at, but some of the species leave a very unpleasant smell, which is apt to re main a considerable time on the articles which they have passed over. The largest of the genus is, as its name imports, the B. gigantea, a native of many of the warmer parts of Asia, Africa, and South America, of which the following account is given by Drury in his " Exotic Insects." " The cock-roach," says he, " are a race of pestiferous beings, equally noisome and mischievous to natives and strangers, but particularly to collectors. These nas ty and voracious insects fly out in the evenings, and commit monstrous depreda *ions : they plunder and erode all kinds Of victuals, drest and undrest, and damage all sorts of clothing, especially those which are touched with powder, poma turn, and similar substances ; every thing made of leather, books, paper, and va rious other articles, which, if they do not destroy, at least they soil, as they fre quently deposit a drop of their excre ment where they settle, and some way or other by that means damage what they cannot devour. They fly into the flame of candles, and sometimes into the dishes ; are very fond of ink and oil, into which they are apt to fall and perish. In this case they turn most offensively pu trid, so that a man might as well sit over the cadaverous body of a large animal, as write with the ink in which they have died. They often fly into person's faces or bosoms, and their legs being armed with sharp spines, the pricking excites a sudden horror not easily described. In old houses they swarm by myriads, mak ing every part filthy beyond description wherever they harbour, which in the day-time is in dark corners, behind all sorts of clothes, in trunks, boxes, and in short every place where they can lie con cealed. In old timber and deal houses,
when the family is retired at night to sleep, this insect, among other disagree able properties, has the power of making a noise, which very much resembles a pretty smart knocking with the knuckle upon the wainscotting. The B. gigantea, in the West Indies, is therefore frequent ly known by the name of the drummer. Three or four of these noisy creatures will sometimes be impelled to answer one another, and cause such a drumming noise, that none but those who are very good sleepers can rest for them. What is most disagreeable, those who have not gause curtains are sometimes attacked by them in their sleep : the sick and the dy ing have their extremities attacked, and the ends of the toes and fingers of the dead are frequently stripped both of the skin and flesh. This insect is not at pre sent known in Europe, though many of the other species, of which Gmelin enu merates 47, have been introduced by ships from the warmer regions, and are become nuisances in our houses. It has been supposed that the gigaritea has been seen once at least in our own country, concerning which Mouffet writes : " I hare heard from people worthy of credit, that one of the blattx was found on the roof of Peterborough church, which was six times larger than the common blatta, and which not only pierced the skin of those who endeavoured to seize it, but bit so deep as to draw blood very copi ously : it was as large as one's thumb, and being confined in the cavity of the wall, after two or three days it made its escape, unnoticed by any one." In Asia this species is as large as a good sized hen's egg. B. orientalis, or black cock roach, is found in America, and has long been naturalized in Europe : female with mere rudiments of wing-cases and wings : egg subcylindrical, with a crenate ridge, and half as large as the abdomen. B. awe-, ricana is native of America, and has of late years appeared in Europe, having been taken over in raw sugar. It is of a feruginous colour, the shield of the thorax whitish behind. B. irrorata is nearly as large as B. gigantea, and is 1 native of New Holland ; head pale ; front subferuginous ; the hind margin brown ; wing-cases with an abbreviated black line at the base.