_Treatment._ Put the infected seeds in an air-tight box or bin, placing on the top of the pile a dish containing carbon disulphide, a tablespoonful to a bushel of seeds. The fumes of this substance are heavy and will pass through the mass of seeds below and kill all the weevils and other animals there. The bin should be closely covered with canvas or heavy cloth to prevent the fumes from being carried away by the air. Let the seeds remain thus from two to five days. Repeat the treatment if any weevils are found alive. Fumigate when the temperature is 70 deg. Fahrenheit or above. In cold weather or in a loose bin the treatment is not successful. _Caution:_ Do not approach the bin with a light, since the fumes of the chemical used are highly inflammable. =The Hessian Fly.= The Hessian fly does more damage to the wheat crop than all other insects combined, and probably ranks next to the chinch bug as the second worst insect enemy of the farmer. It was probably introduced into this country by the Hessian troops in the War of the Revolution. [Illustration: FIG. 169. THE HESSIAN FLY] In autumn the insect lays its eggs in the leaves of the wheat. These hatch into the larvae, which move down into the crown of the plant, where they pass the winter. There they cause on the plant a slight gall formation, which injures or kills the plant. In the spring adult flies emerge and lay eggs. The larvae that hatch feed in the lower joints of the growing wheat and prevent its proper growth. These larvae pupate and remain as pupae in the wheat stubble during the summer. The fall brood of flies appears shortly before the first heavy frost. _Treatment._ Burn all stubble and trash during July and August. If the fly is very bad, it is well to leave the stubble unusually high to insure a rapid spread of the fire. Burn refuse from the threshing-machine, since this often harbors many larvae or pupae. Follow the burning by deep plowing, because the burning cannot reach the insects that are in the base of the plants. Delay the fall planting until time for heavy frosts. =The Potato Beetle; Tobacco Worm.= The potato beetle, tobacco worm, etc., are too well known to need description. Suffice it to say that no good farmer will neglect to protect his crop from any pest that threatens it. The increase, owing to various causes, of insects, of fungi, of bacterial diseases, makes a study of these pests, of their origin, and of their prevention a necessary part of a successful farmer's training. Tillage alone will no longer render orchard, vineyard, and garden fruitful. Protection from every form of plant enemies must be added to tillage. [Illustration: FIG. 170. SPRAYING THE ORCHARD One way of increasing the yield of fruit]