TOBACCO PESTS. The tobacco flea-beetle (Epitrix paruula) is generally distributed throughout the United States, It is a minute, oval, reddish-brown species occurring upon many solanaceous plants, which makes its appearance in July, attacking the tobacco leaves. which soon present a spotted appearance. Afterwards these spots become holes and the leaf is practically de stroyed. In the larval state the insect feeds upon the roots. The small holes eaten by the beetles become the entrance points of bacteria, which start a leaf-disease which may be more injurious to the plant than the actual work of the beetles.
The so-called horn-worms, or 'horn-blowers; of to bacco are the larva of two sphingid moths (Proto parce caroli.na• and Phlegcthontius ccleus.), large green caterpillars with oblique white stripes on the sides of the body, and the anal end of the body armed with a horn. These larvie live upon to bacco leaves, transform to pupa; under the ground, and the moths issue in May or June. The eggs are laid singly on the under side of the tobacco leaf just at nightfall. There are two generations each summer in a large part of the tobacco-grow ing region. Two insects, both larvm of noctuid moths, are known as 'bud-worms' in tobacco fields. They are Heliothis armiger (also known as 'boll worm' (q.v.), corn-ear worm, and tomato fruit worm), which preferably lives in the ears of corn until the grain becomes hard, and therefore works in tobacco usually only toward the end of the season, and Heliothis rhcritc. The latter is the true bud-worm. (See Colored Plate of AMER ICAN MOTHS.) The adult is a small greenish moth, and the larva is found in the bud of the plant about the time it is ready to top. They transform to pupae under the surface of the ground. A true bug (Dicyphus minimus) dam ages the second crop in late tobacco by punctur ing the leaves and sucking the cell sap. Infested leaves become yellowish in color, somewhat wilt ed, and the older ones eventually split in places, becoming ragged. The bug, when immature, lives on the under side of the leaves. but the adults live both above and below.. The eggs are deposited singly in the tissues of the leaf and hatch after four days. One entire generation is produced in fifteen days. Several other sucking bugs punc ture tobacco leaves, but are not serious enemies of the crop, except, perhaps, the 'green bug' (Euschistus variolarius).
The tobacco leaf-miner, or 'split worm' (Phtho rimwa operculcIla) hatches from eggs laid upon the leaves by a minute grayish moth, and bores between the surfaces of the leaf, making a flat mine often of considerable size. This insect is a cosmopolitan species and
works upon potatoes as well as upon tobacco, bor ing into the tubers as well as the leaves. Several species of cutworms (q.v.) damage the tobacco plant early in the season. A mealywina. (q.v.) (Aleyrodcs tabaci) damages the leaves of tobneeo in Europe and in the Southern United States. The common mealy-bug (Dactylopius cifri) af fects the plant, as also do several species of plant lice. The tobacco thrips (Thrips tabaci) is an important enemy of tobacco in Bessarabia. It occurs upon many plants in the United States, especially upon onions, but has not been found upon tobacco.
Most of the insects mentioned may be destroyed by spraying the plants with an arsenical mixture. Nearly all of them feed upon solanaeeous plants, and an excellent remedial measure is to allow a few weeds of this family, such as Solanum nigrunt or Datum stramonium, to grow in the immediate vicinity of the field which is to be planted in tobacco. These weeds will act as traps for nearly all of the early tobacco insects, and they can be treated with heavy doses of Paris green for the leaf-feeding species, and with a spray of kerosene emulsion and water for the sucking bugs. Large numbers of these insects can be killed in this way, greatly to the protec tion of the young tobacco plants when they are set out.
Dried tobacco is attacked and frequently ruined, even after having been made up into cigars and cigarettes, by the so-called cigarette beetle (Lasioderma serricorne), an insect which works not only in tobacco, but in many other dried herbs as well as certain dried foods. It is a cosmopolitan species, and multiplies rapidly throughout the greater part of the year, feeding both as larvae and as adults. The 'drug-store beetle' (Sitodrepa panicea) and the common rice weevil (Calandra oryza ) also feed upon dried tobacco. These insects are destroyed by fumi gating the rooms or the establishments in which they occur with bisulphid of carbon or hydro cyanic acid gas.
All of the species above mentioned occur in the United States, although several of them are eos mopolitan. In Europe 144 species are recorded as occurring in tobacco fields. The most impor tant of these, among the species which do not occur in America, is a tenebrionid beetle (Opa trunt intermedium), which injures the plant by attacking the stems under ground. Consult How ard, The Principal Insects .1 ffecting the Tobacco Plant (Washington, 1900).