FLAT-HEADED BORER.
The adult, [fig. 10], is flat, about three-eighths of an inch long, of a greenish black with coppery reflections. They appear about the last of May and deposit eggs from then until September. They generally lay their eggs in a diseased portion of the tree, where it has been bruised, or sun-scalded, or in trees of weak vitality, in bad health from lack of cultivation or moisture, or from soil poverty. The eggs are small and yellowish, and are found singly or in numbers in crevices in the bark. The larva, or borer, [fig. 11], when young, is yellowish, with a broad, flat head; it soon bores to the sap-wood, where it feeds. At this time it is easily discovered by the "castings" from the opening. As they become older and larger they bore into the harder wood, making flattened chambers. In about a year they gnaw a channel to the outside, excepting a thin layer of bark, and backing a little way they crowd castings to the front and change into the perfect insect, emerging about the last of May.
Remedies. Keep the tree thrifty, free from bruises or sun-scald, and the flow of sap will drown them. If any are detected by the castings, cut in, and use a hooked wire to pull them out. Some washes will deter the female from depositing eggs. For instance: Equal parts of soft soap and sal soda, with enough crude carbolic acid to give a strong odor. Apply with a brush several times in a season, especially where the bark appears unhealthy.