Locust, Black

Locust Borer: Formulations of carbaryl and chlorpyrifos (Dursban 50W only) are labeled for locust borer management.
Management Hints: Adults may be found in early September feeding on goldenrod pollen. They do not harm the tree, but larvae affect the wood with their feeding and tunneling. Fertilization and irrigation will promote a healthy plant and may reduce successful attack by this pest. Spray bark of trunk and large branches in late August through September. There is one generation per year. (p. 274)

Locust Leafminer: Formulations of azadirachtin, bifenthrin (Bifenthrin Pro Multi-Insecticide, Onyx Insecticide, Talstar F, Talstar Lawn & Tree Flowable, Talstar GC Flowable, Talstar Nursery Flowable, and TalstarOne Multi-Insecticide only), chlorpyrifos (Dursban 50W only), cyfluthrin and imidacloprid, deltamethrin (5SC only), imidacloprid, lambda-cyhalothrin (for adult leafminers), naled, oxydemeton-methyl, permethrin, and pyrethrins and piperonyl butoxide are labeled for leafminer management. Marathon 1% G and Marathon 60 WP are labeled for use only on plants grown in containers, flats, benches, or beds.
Management Hints: Injury by this insect is primarily a problem on black locust. In a severe infestation, the combined feeding by larvae and adults may destroy the foliage of a tree in July and again in September. In some areas of Pennsylvania, hillsides covered with black locust may turn completely brown. Manage overwintering adults when they start feeding in the spring as black locust foliage develops. First generation adults are frequently seen in July. Repeat applications may be necessary since two generations of this leafmining beetle occur annually in Pennsylvania. (p. 190)