T68 POTATO (SWEET) POTATO BUG central Michigan. In the southernmost states pieces of the roots are sometimes planted, but even there the yield is better from sets or slips, a method absolutely necessary in northern lo- calities. To procure the sets, the potatoes are laid upon the earth of a hot-bed, splitting the larger roots lengthwis'e and placing them with the cut side down, and covered with three or four inches of light, rich soil; sprouts soon start, and when these have made roots they are broken off to be planted, and the pota- toes returned to the hot-bed to furnish more sprouts. The best method is to plant them in ridges, and this is essential to success in north- ern localities. The usual plan is to lay down a strip of well rotted manure and throw a fur- row toward it by ploughing on each side, thus forming a ridge over the manure ; other ridges are made in the same way, their tops about 3 ft. apart ; after the ridges are well dressed into shape by means of the hoe and rake, the sprouts or sets are planted upon them about 15 in. apart. The after culture consists in keeping the ridges clear of weeds until the vines cover them ; the vines late in the season strike root at the joints, and it is necessary in northern localities to prevent this by moving them occasionally, in order to throw all the strength into the roots. In countries where there is no frost the plant is allowed to take root at the joints, as in this manner it per- petuates itself and does not need replanting. The vines are killed by a slight frost, after which the roots should be dug at once, dried, and stored. In the southern states they are kept in piles of 30 or 40 bushels in a well drained place, and covered with leaves or straw, and finally with earth. In colder regions more care must be given ; small quantities are preserved in barrels or boxes packed in per- fectly dry sand, and placed in a warm cellar ; on a large scale they are stored in a house, where the temperature is kept at about 60 all winter. Several plants related to the sweet potato have in their roots a purgative resin, similar to that of jalap (which is also closely allied), but this in the sweet potato is replaced by sugar and starch, though there appears to be a trace of the principle, as many persons are unable to eat them on account of the purging they produce. In this country they are used as a vegetable to be eaten with meats, while in Mexico the pro- portion of sugar in the root is much larger, and they are there regarded rather as a sweet- meat. Persons at the north estimate the sweet potato, as they do the common one, by the amount of starch, as indicated by its mealiness, while in southern climates the amount of sugar is the chief consideration; those which con- tain much sugar are never light and starchy, but, being always moist and "soggy" when cooked, would be considered by most persons at the north as unfit for food. Not many years ago the northern markets were mainly supplied from the Oarolinas and Georgia, but they now come mostly from New Jersey, the soil of which is well adapted to the culture. According to the census of 1870, the total pro- duction of sweet potatoes in the United States was 21,709,824 bushels, of which North Caro- lina produced 3,071,840, Georgia- 2,621,522, Texas 2,188,041, Alabama 1,871, 360, Mississippi 1,743,432, New Jersey 1,550,784, South Caro- lina 1,342,165, Tennessee 1,205,683, and Louisi- ana 1,023,706. Every state produced some, the fewest being 96 bushels in Vermont. POTATO BUG, a term popularly used to desig- nate any insect that affects the potato injuri- ously. There are more than a dozen such in- sects in the United States ; but in view of its interesting history and of its being incompara- bly the most serious and destructive enemy of FIG. 1. Doryphora 10-lineata. a. Eggs, b, b, b. Larvae of different sizes, c. Pupa. <, d. Beetle, e. Enlarged wing cover, showing character of punctures. /. Enlarged leg. that plant, the term has come to be applied more especially to the Colorado potato beetle, originally described as dorypliora 10-lineata by Thomas Say. The generic names poly- gramma, myocoryna, and leptinotarsa, applied to it by later European writers, are ignored by American authorities, as founded upon too trifling characters. This insect is indigenous to the cations and table lands of the Rocky mountains, and began its eastern march from Colorado. In its native habitat it feeds upon various wild species of solarium, particularly S. rostratum and S. cornutum, peculiar to that region. As civilization advanced west- ward, and field and garden crops were grown within the limits of its natural range, it soon acquired the habit of feeding upon the culti- vated potato. Abundance of food stimulated its prolificness, and it gradually extended its ravages eastward. The first accounts of its injurious propensities were published in 1859- '60, and within 15 years it has spread over the entire potato-growing region of the United States and Canada, and has even excited alarm in Europe. In 1861 it had advanced
