Page:The American Cyclopædia (1879) Volume V.djvu/424

420 COTTON WORM COUCH GRASS of a color resembling the leaf; the period of incubation is variously stated from 6 to 15 days, depending probably on the heat of the season ; the time of hatching is at night, and the young begin to eat very soon, growing very rapidly ; the skin is changed several times before they attain their full growth. In 15 to 20 days after attaining the full size they cease to feed, and form an imperfect cocoon of a leaf and silk ; in this the chrysalis state is passed, from 10 to 12 days ; after this the moths lay their eggs, and die after a period of about a week, or, according to some observers, survive mild winters. This insect is in some years exceedingly destructive to the cotton, some- times cutting off the entire crop of certain dis- tricts ; it appears often in a sudden and unac- countable manner, as if it must migrate from the south. They were first noticed as destroy- ers of cotton about the year 1800, since which their ravages have been more or less serious al- most every year ; it is believed by some that they appear at intervals of three years in the same districts, and that their greatest ravages occur after intervals of 21 years; the years 1804, 1825, and 1846 were remarkable in this respect ; the time of year varies from June to October. A moderate degree of cold is suffi- cient to kill them, though moisture and strong winds do not appear to disturb them. They devour both the short-staple and the long- staple cotton, and rarely, if ever, touch any other plant. When they appear early in the season, there are usually three broods. Dr. Burnett is of opinion that this insect comes from South America, and that the last brood perish entirely, either from cold or starva- tion, leaving no progeny behind them. Fires in the fields have been recommended as at- tracting and destroying this moth ; white cot- ton flags, about a yard square, are said to at- tract it, and to be nsed as deposits for the eggs ; great numbers may be caught by molas- ses and vinegar spread on plates. But these and similar contrivances will be of little av.ail until the exact appearance of the first moths is ascertained; then their speedy destruction would prevent the production of the second and third broods, and thus limit, if it did not arrest, their ravages. Another insect destroy- ing great numbers of cotton buds is the boll- worm moth, belonging to the same tribe of noctua, and probably to the genus Tielioihes. This is a tawny, yellowish moth, which may be seen toward evening, in summer and au- tumn, hovering over the cotton blooms, and depositing a single egg in each flower ; the egg is hatched in three or four days, and the worm eats its way into the centre of the boll, caus- ing its premature fall ; the insect instinctively leaves the boll when it is about to fall, and enters another, and finally attacks the nearly matured bolls, rendering the cotton rotten and useless. The caterpillars have 16 feet, creep- ing with a gradual motion, unlike the true cot- ton worm ; they vary much in color, some being green, others brown, but all more or less spot- ted with black, and having a few short hairs. A single moth will lay 500 eggs, and, as three broods are produced in a year, a whole field will be very soon infested with them. These are the two greatest enemies on the cotton plantations, and the same remedies are effec- tual against both. In the "Agricultural Re- port of the Commissioner of Patents" for 1855 is an excellent article by Townend Glover on the insects found on the cotton plant, on the stalk, on the leaf, on the terminal shoots, on the flower, and on the boll, whether injurious, beneficial, or indifferent. Many cotton worms are destroyed by spiders, beetles, and ichneu- mon flies. COTYS, or Cotytto, a Thracian female divinity, whose festival (the Cotyttia) resembled that of the Phrygian Cybele. It was held at night, and celebrated on hills with licentious revelry. COUCH, Richard Qnillar, an English scientist, born at Polperro, Cornwall, March 14, 1816, died in Penzance, May 8, 1863. He was a surgeon in Penzance, added a third part, on the zoophytes and calcareous corallines of the Cornish coast, to his father's work on the Cornish fauna, and contributed extensively to periodical publications, relating to physiology and geology. His papers on the diseases and mortality of miners, published by the polytech- nic society of Cornwall, have been translated into French. COUCH GRASS (triticum repens, Linn.), a troublesome plant which infests arable lands, and is known by a great variety of names in different localities, such as twitch, witch, quitch, squitch, quack, quake, dog grass, chandler grass, wheat grass. The plant is about 2 ft. high, hav- ing rough leaves, somewhat hairy, and trailing at the lower joints, and propagates both by its seed and its jointed roots and stems. Although a grass, it performs the office of a vile weed, being an insidious creeper, multiplying and ramifying itself in all directions. Its scraggy roots go deep into the soil, and take firm hold. Each joint can produce a new plant, which in turn, if not destroyed, will produce others beyond number. Gathering and burning the grass with all its roots is the only effectual remedy against it. A crop of turnips, whose broad leaves exclude sun and air, and the frequent disturbance of the soil in hot, dry weather, are useful in subduing it. Cutting it with the hoe in wet weather only Couch Grass (Triticum repens).