Borer (Sesia scituta). — A wood-boring caterpillar working in the sapwood.
Treatment. — Digging out. Twig-girdlers. — See under Persimmon below. Rose-beetle. — See under Grape and Apple, pp. 308, 322. Round-headed Borer. — See under Apple. Slug. — See under Cherry, p. 313.
Twig-girdler (Oncideres cingulatus). — A brownish-gray beetle, about one-half inch long, which girdles twigs in August and September. The female lays eggs above the girdle. The twigs soon fall.
Remedy. — Burn the twigs, either cutting them off or gathering them when they fall. Twig-pruner. — See under AppLE, p. 309. Persimmon. White Peach-scale (Diaspis pentagond).
Remedy. — Lime-sulfur when the trees are thoroughly dormant. Twig-girdlers (Oncideres cingulatus and 0. texana). — Dark gray long-horned beetles that girdle the twigs, causing them to drop. Remedy. — Pick up and burn fallen twigs in fall and winter. Pineapple. Katydid (Acanthacara similis). — A large katydid which attacks, among other plants, the leaves of the pineapple. Remedy. — Arsenicals, before the plants are mature. Mealy-bugs (several species). — These mealy white insects attack the plant at the base of the leaves, usually underground.
Treatment. — Set only clean plants, or dip them in resin wash or kerosene emulsion. In the field apply tobacco dust freely in the bud before the bloom begins to appear, or spray with kerosene emulsion. Red-Spider (Stigmaeus floridanus). — Minute mites occurring in great number at the base of the leaf, where they induce rot. Treatment. — Tobacco dust applied to bud.
Plum. Canker-worm. — See under Apple, p. 306. Curculio (Conotrachelus nenuphar). — Larva, a whitish grub, feeding in the fruit.
Remedies. — Arsenate of lead, 6 pounds to 100 gallons of water; apply as soon as the calyx falls, and repeat two or three times at intervals of about ten days. Jarring the beetles on sheets very early in the morning, beginning when trees are in flower, and continuing from four to six weeks, is probably the most sure procedure. There are various styles of sheets or receptacles for catching the insects as they fall from the tree. Clean culture. Flat-headed Borer. — See under Apple. Pear-twig Beetle. — See under Pear, p. 326. Plum-gouger (Coccotorus prunicida). — A small larva, feeding upon the kernel of the plum. The beetle bores a round hole in the plum instead of making a crescent mark, like the curculio. Remedy. — Catch the beetles over a curculio-catcher. Scale (Lecanium corni). — A large circular scale occurring on plum (and perhaps other) trees in New York.
Remedy. — Thorough spraying with kerosene emulsion, one part to five of water, in the winter. More dilute emulsion or tobacco extracts in midsummer, when the young insects are on the leaves and young shoots. Slug. — See under Cherry, p. 313. Twig-pruner. — See under Apple, p. 309. Poplar. Cottonwood Leaf-beetle (Lina scripta). — A striped beetle feeding on the leaves and shoots of poplars and willows. Remedy. — Arsenicals. Willow-worm. — See under Willow, p. 336. Poplar Borer (Cryptorhynchus lapathi).— A whitish grub burrowing in the wood.
Treatment. — In nurseries spray thoroughly about the middle of July with arsenate of lead to kill the parent beetles. Potato. Colorado Potato-beetle (Leptinotarsa decemlineata).— Beetle and larva feed upon the leaves.
Remedies. — Arsenicals, either dry or in spray, about a third stronger than for fruits. Hand-picking the beetle. Stalk-weevil (Trichobaris trinotata). — A grub boring in the stalk of the potato near or just below the ground. Serious at the West and in some places eastward.
Remedy. — Pull all infested vines as soon as they wilt, and spread them in the sun where the insects will be killed. Burn the vines as soon as the crop is harvested. Destroy all solanaceous weeds.