This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
The young nymphs may be killed by thorough spraying with "Black Leaf 40" tobacco extract, one pint in one hundred gallons water, adding four pounds of soap, (1) when blossoms show pink, (2) when the last of the petals are falling.
Catalogue of Insects, continued.
These red-headed, black-and-yellow-striped caterpillars with a red hump on the fourth segment often attract attention in August and September by feeding in colonies on the ends of the branches.
Spray for the young caterpillars with arsenate of lead, four pounds in one hundred gallons of water. As they are most troublesome on newly planted trees the older caterpillars may be shaken to the ground and crushed under foot.
A minute yellow or green larva feeding upon the upper surface of the leaves, causing the lower surface to turn brown. The cocoons are white and slender, and are laid side by side upon the under side of twigs, where they are conspicuous in winter.
Lime-sulfur while tree is dormant. Arsenicals for the larvae in summer.
A yellowish white grub with dark brown head, about 1 inch long when mature. It is said to remain in the larval state three years. The parent beetle is silvery white on the head and beneath; the thorax and wing-covers are light brown: two silvery white stripes extend from the head to the tip of the wing-covers. The eggs are laid in slits in the bark, mostly in June.
Keep the beetles from laying eggs by spraying the trunks several times during the spring and summer with kerosene emulsion or by coating them with an alkaline wash made from soap, caustic potash, and carbolic acid. Tarred paper tree-protectors well tied at the top, or wire mosquito-netting protectors closed at the top and encircling the trunk so loosely that the beetles cannot reach the bark, are effective in preventing egg-laying. Practise clean cultivation, and do not let water sprouts or other rank vegetation encircle the base of the tree.
Dig out the borers whenever they can be located by discolored bark or by the sawdust thrown out of the burrow.
This scale is nearly circular in outline and about the size of a pinhead. When abundant it forms a crust on the branches, and causes small red spots on the fruit. It multiplies with marvelous rapidity, there being three or four broods annually, and each mother scale may give birth to several hundred young. The young are born alive, and breeding continues until late autumn, when all stages are killed by the cold weather, except the tiny, half-grown, black scales, many of which hibernate safely.
Spray thoroughly in the fall after the leaves drop, or early in the spring before growth begins, with lime-sulfur wash, one gallon in eight gallons of water, or miscible oil, one gallon in fifteen gallons of water. When badly infested, make two applications, one in the fall and another in the spring. In case of large, old trees, 25 per cent crude-oil emulsion should be applied just as the buds are swelling.