was no opportunity for plant attack. Most cases of injury are due to the operations of the beetles, and damage is more pronounced on young plants, older growth appearing in some cases exempt from attack, owing to its more woody texture. Injury may be accomplished both by hibernated individuals in the spring from April to June, according to locality, and by recently transformed specimens in late summer and autumn.

The species is with little doubt single-brooded. Pupation takes place in an oval cavity in the earth, and hibernation, without much doubt, occurs in the adult condition. The favorite food of the beetle is evidently carrot, and after this corn, parsnip and celery are chosen. Sweet and Irish potato are subject to much damage, as are also sunflower, dahlia, sugarbeet and sometimes cotton. The beetles usually feed beneath the surface; corn is cut just above the roots, and root crops are punctured with holes. Sometimes a crop appears in good condition, judging from the tops alone, but when the plants are pulled injury becomes manifest. Entire plantings have been destroyed by the beetles, and the roots of tubers rendered unmarketable on account of their ravages. They gnaw into the roots of celery, dwarfing and killing the plants, and eat the bark from the root. They sometimes imbed themselves in tap roots and may penetrate the earth to a depth of seven inches. As many as fifty beetles have been found about the roots of a single plant.

METHODS OF CONTROL.-When this insect is present in large numbers there is little, owing to its working underground, that can be accomplished in the line of control. The beetles are strongly attracted to electric lights, but it is not certain that they could be lured from the field after beginning to feed. It is reported that lime scattered through infested fields has apparently driven the beetles away. After the crop has been harvested, if the insects continue in numbers in the ground, it would

be profitable to turn in hogs or chickens. Crop rotation and other white-grub remedies should be practiced.

The Parsnip Webworm (Depressaria heracliana DeG.).-The parsnip webworm is injurious to the seed of parsnip, but for some reason, at least in the experience of the writer, prefers the wild carrot as a breeding plant. The moth is grayish buff, or pale ochraceous, with the fore-wings marked with fuscous (fig. 120, e). The larva is pale yellow, greenish or bluish gray, marked with black, piliferous spots, and with bluish black head

Fig. 120.-Parsnip we oworm. a, Moth; b, c, caterpillars: d, chrysalis; e anal segment of same: f. umbel of parsnip, webbed together by caterpillar. a e. Enlarged; f. somewhat reduced. (After Riley.)

and thoracic plate, as figured (a, b). The species is of general occurrence through the northern portions of Europe and our Atlantic States and Canada westward to Michigan. Wild carrot and parsnip, which are altogether too abundant in fields throughout that section, yield it a sufficiency of food and in some years it is difficult to find these weeds that are not affected by the webworm. The larvæ weave the flower heads (f) together until these are contracted into masses, with abundant excrement as a covering. Within the domicile thus formed the larvæ dwell. After they have consumed the flowers and unripe

seeds and are nearly mature, they enter the stems, feed on the soft lining, and transform to pupa. They sometimes destroy newly-sown parsnip, eating the tender leaves, but in attack on older plants they eat the umbels or flower heads and the interior of the stems.

REMEDIES. A thorough spraying with arsenicals will destroy this webworm. To prevent injury by it avoid planting parsnips in or near waste places which have become overrun with wild

carrot.

MISCELLANEOUS INSECTS.-Among other insects injurious to celery the tarnished plant-bug is an important species. It is figured and described on pages 87 and 88. The cotton leaf-bug (Calocoris rapidus Say), a species of somewhat similar habits and appearance (fig. 120x), also attacks celery and is amenable to the same remedial treatment.

CHAPTER XII

INSECTS INJURIOUS TO SWEET CORN

A greater number of species of insects have been recognized as attacking Indian corn than any other plant grown as a vegetable. Although, properly speaking, corn is a field crop, it is also grown for the sake of the unripe ears which are classified as vegetables. What insects will attack field corn will also attack the garden variety, but for present purposes it will not be necessary to treat of any except the more important habitually garden-inhabiting species, and only a few of these need be considered at all in detail. Many of them are general feeders and have been considered in preceding paragraphs.

The corn-feeding species of insects recognized in 1896 were 214 in number, and of these 18 attacked the seed, 27 the root and lower portions of the stalk, 76 the stalk above ground, 118 the leaf, 19 the tassel and silk, and 42 the ear. The remainder attacked the stored product. It is safe to say that at the present writing (1907) at least 350 species are on record as concerned in attack on corn.

The Corn Root-aphis (Aphis maidiradicis Forbes).-Concerning this species, Dr. S. A. Forbes wrote in 1896: “No insect affecting corn is more deserving of the attention of farmers and entomologists at the present time than the corn root-aphis. It ranks as a corn pest with the chinch bug and the army worm, less injurious at any one time than these are locally and occasionally, but overtaking them, on the other hand, by its general distribution and the constancy of its attack." This root-aphis does its principal injury while corn is small. The dwarfing of a plant in patches with a yellowing or reddening of the leaves, and

a lack of thrift and vigor, are the outward manifestations of injury. Another indication is the presence of numerous small brown ants which attend this species and without which it probably could not exist.

The corn root-aphis is bluish green, slightly whitened by a waxy bloom. The body is oval, and the nectaries are erect or