Maggot. — See under Cabbage, p. 311. Celery. Carrot Rust-fly (Psila rosae). Minute whitish yellow maggots infesting the roots and stunting the plants.

Preventive.— Late sowing and rotation of crops. Celery or carrots should not follow each other. Celery Caterpillar (Papilio polyxenes).—A large green caterpillar, ringed with black and spotted with yellow, which feeds on the leaves.

Treatment. — Hand-picking as soon as observed. Celery Leaf-tyer (Phlycaenia ferrugalis). — A greenish caterpillar, feeding on the under side of the leaves.

Treatment.— Spray with arsenicals while the larvae are still young. Little Negro-bug (Corimelaena pulicaria). — Glossy black bugs one-eighth inch in length, which collect in clusters in the axils of the leaflets and cause the plants to wilt.

Treatment. — Kerosene emulsion or tobacco extract. Cherry. Canker-worm. See under Apple, p. 306. Plum-curculio. See under Plum, p. 329. Rose Beetle. See under Apple and Grape, pp. 308, 322. Slug (Eriocampoides limacina). — Larva; one-half inch long, blackish and slimy, feeding upon the leaves ; two broods. Treatment. Arsenicals, hellebore, tobacco extract. Aphis {Myzus cerasi). Blackish plant lice infesting the leaves and tips of new growth.

Treatment. Spray as soon as the first lice appear with whale-oil soap or tobacco extract. Chestnut. Weevil {Balaninus proboscideus and B. rectus). — A grub working in chestnuts, making them wormy. The weevil is a curculio-like insect.

Preventives. — Destroy wild trees where the insects breed. Plant the most immune varieties. Gather and destroy the infested nuts immediately after they fall. Chrysanthemum. Cabbage-looper. — See under Lettuce, p. 322. Chrysanthemum Leaf-miner (Oscinis sp.).— Works on the leaves of the chrysanthemum. Remedy. — Hand-picking. Clover. Flower-midge (Dasyneura leguminicola). — An orange-red maggot infesting the flower-buds, where they consume the contents of the ovary.

Preventives. — Cut the first crop for hay as early as possible, thus destroying the undeveloped larvae of the first brood. In the latitude of Illinois this should be done before June 25. Seed-chalcis (Bruchophagus funebris). — A white grub found inside the seed.

Preventive. — Same as for Flower-midge, above. Destroy all volunteer clover plants. Seed-caterpillar (Enarmonia interstictana). — A small whitish or orange caterpillar infesting the heads.

Preventive. — Early cutting of first crop, as for Flower-midge. Root-borer (Hylastinus obscurus). — Small white grub burrowing in the roots.

Preventive. — Plow under badly infested fields as soon as possible after cutting. Hay-worm (Hypsopygia costalis). — A brownish caterpillar three-fourths inch long, infesting stacked or stored clover.

Preventive. — Remove old clover hay before putting in the new. Place stacks on log or rail foundation, and salt the lower layers. (Illinois Experiment Station.) Corn. Corn-root Aphis( Aphis maidiradicis). — A bluish green aphis infesting the roots.

Preventives. — A short rotation period in corn, especially in dry years. Deep and thorough and repeated stirring of old corn ground in fall and spring as a preparation for corn-planting. Maintenance and increase of the fertility of the soil. White Grubs (Lachnosterna spp.). — The large white curved larvae of the common June beetle.

Preventives. — Rotation of crops ; do not let corn follow sod, but let a crop of clover or clover and oats intervene. To help clear sod land of grubs, pasture to hogs any time between April and October. To prevent laying of eggs in corn-field, keep the ground free from weeds during May and June. Thorough cultivation and heavy fertilization. Northern Corn Root-worm (Diabrotica longicornis). — A whitish grub two-fifths inch long, which burrows in the roots.

Preventive. — Crop rotation ; corn should not follow corn.