Tar
Of late years, Tar has come to be regarded as a most valuable remedy against the ravages of many insects in gardens; and it is also used for the protection of farm crops. References have been made to it in treating of the remedies for insect attacks under the names of various plants; but it may be of use to give here a summary of the best methods of employing it. As a preventive of attack, Tar is employed against such larvae as conceal themselves underground during the day, and crawl up tree-trunks at night. It is also used to prevent the ascent of the females of the Winter Moths (see Hybernia and Winter Moth), and other female insects that cannot fly. These insects are thus prevented from reaching the leaf and flower-buds for egg-laying, and the trees are saved from destruction by the larvae. The Tar may be applied directly on the bark, in a broad ring, mixed with an equal bulk of cart-grease, or with one-third part of fish-oil; the latter being added to prevent the Tar from losing its stickiness in frosty weather. On warm days, this mixture becomes fluid, and sinks into the bark; and trees with thin bark are liable to be injured by it. This difficulty may be overcome by placing a belt of straw-rope, or cloth, or strong paper, round the trunks that might be injured, and putting the Tar on the belt.
Tar-water and Spirits of Tar are also used as preventives; sand, well saturated with them, being laid round the base of each stem, to prevent the passage of insects to the plant. Tar-water is sometimes syringed over plants, as, in weak solutions, it is a good insecticide, and, by its smell, also deters insects from laying eggs on plants so treated. Tar has been employed with great success for the capture of such insects as the beetles that devour Raspberries (see remarks on INSECTS under Raspberry), Turnips, and other plants, and also against such insects as Frog-hoppers. In America, it has proved itself the most effectual means of capturing the notorious Rocky Mountain Locusts. A light framework of wood is covered with thin wooden boards, cloth, or strong paper, so as to form a shallow tray, and the inside is smeared with Tar. The mode of using the trap varies with the insects to be caught. For catching Raspberry Beetles, and other insects on trees and bushes, the branches are beaten over the tray, and the insects fall into it, and are stuck in the Tar. Against the Turnip Flea, Grass-hoppers, &c., the same method may be employed as against the Rocky Mountain Locusts, viz., dragging the tray along the ground, with something about 12in. or 18in. in front to disturb the insects, and to cause them to leap, when many of them fall into the Tar, and are held fast in it.