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Purple Carrot-Seed Moth (D depressella Their appearance)

(D. depressella). Their appearance, habits, and modes of doing damage, and the best remedies against each, will be found in detail under these heads, but may be summarised here as follows: Psila Rosae is a small, two-winged fly, the grubs of which are slender, white or yellowish, and about 1/4in. long. They burrow into the tap-roots of Parsnips and of Carrots, forming narrow, irregular galleries. The diseased plants show the injury by the outer leaves drooping and turning yellow. It has been found useful, as a remedy, to water the plants with solutions of paraffin (one ounce to one gallon of water) or of alum, or liquid manure; and gas-lime, soot, or sand prepared with tar (one gallon to a barrowful of sand), are all useful applications if dug into the soil.

Tephritis Onopordinis is harmful, inasmuch as the grubs burrow between the surfaces of the leaves of Parsnips, producing large, pale patches, in which the surfaces are separated from each other. These patches are useless for the nutrition of the plant; hence, when numerous, much injury is done to the leaves. One or more grubs are present in each patch. When full-fed, they generally bore through the skin of the leaf, and into the soil, and in it they turn into brown, oval pupae; but sometimes they become pupae in the discoloured patches of the leaves. From the pupae, in a fortnight or so in summer, or after the winter, emerge brown or yellowish two-winged flies, about the size of house flies, with brown-spotted wings and green eyes. The best remedy is to crush the spots, when they are small, between the finger and thumb, or pick off and burn the diseased leaves. The leaves may also be sprinkled with lime, or gas-lime, or soot, to prevent deposition of the eggs. The pupae may be destroyed by digging gas-lime into the soil in autumn and winter, or by paring off and burning 3in. or 4in. of the surface soil. All the moths that need be noticed here belong to the genus Depressaria, a rather large group of insects, included in the Tineina (which see for characters). They vary from a little over 1/2in. to 1in. across the wings. The fore wings are cut square at the tips, and the hind margin of the hind wings is generally notched near the base. The insects are usually grey, reddish-brown, or brown, and the fore wings bear darker spots or streaks. Several of these moths live on umbelliferous plants, in the umbels of flowers, or in pieces of the leaves so rolled as to form tubes. The parts occupied by them are spun together by means of silk, and thus afford them protection from enemies of every kind. When the web is torn, or even if the plant is shaken, the larvae wriggle to the exterior, and drop to the ground, to re-ascend at leisure. When full-fed, they usually bore into stems of the food-plant, and in them become pupae. In this state they frequently hibernate, though some live through the winter as moths. Those larvae that feed on the leaves do comparatively little harm, but those that feed in the umbel eat the flowers and fruits, and do much mischief to the seed crop. The best remedy is hand-picking, or shaking the affected umbels. The larvae readily fall out, and should be trampled upon and crushed before they can crawl away, or again reach the umbels.