Potherb Moths
Under this name are included numerous species of Noctuidae, the larvae of which devour the low-growing garden produce or potherbs, such as Cabbages, Turnips, Beets, Peas, Beans, Carrots, &c. The moths are nearly all dull-coloured, and mostly have a spread of wings of 1 1/2in. to 2 1/4in. They belong to groups for the most part already discussed (see Mamestra, Noctua, Plusia); hence, it is unnecessary to repeat here what is to be found under these headings, as to the form and habits of the moths. The larvae are long and worm-like, not hairy, and generally dull green, brown, or yellowish in colour, with longitudinal lines and black dots, though sometimes ornamented with brighter colours. They live hidden between the leaves of their food-plants, or underground upon roots of Turnips and other plants, and, unless looked for, are very seldom to be seen. Owing to their mode of life, they are apt to remain in Cabbages and other vegetables till cooked and sent to the table. It is hardly possible to get rid of them entirely, and the more so, since most of them feed largely on weeds, as well as on garden produce. Hadena oleracea sometimes gets the name of Potherb Moth, though not peculiarly destructive. For its appearance, The front wings are reddish-brown; there is a nearly white line parallel to the hind margin, and bent so as form a W nearly in the middle; the stigmas near the middle of the wing are margined with white scales, and the one nearer the tip (the reniform stigma) is of a dull ochreous colour. The hind wings are grey-brown, paler towards the base, and the body is grey-brown. The larva is usually some shade of dull greenish-grey, with many white dots, and a smaller number of regularly-arranged black dots along the body. The back is marked with three dull, darker lines lengthwise, and there is a white line running along the lower part of each side. The pupa is protected in an earthen cocoon.
Remedies. The larvae of all kinds of Potherb Moths should be destroyed whenever seen. Hand-picking, though slow, is, perhaps, the surest method. Gas-lime is a very useful application, either used fresh in a narrow ring on the soil, round, but not touching, the stems of the plants, or after some months' exposure to air, when it should be dusted over the plants, so as to allow it to get between the leaves. Soot has also been successfully employed. Of course, such remedies render it necessary to thoroughly wash the plants before using them at table. The pupae are often exposed when the soil is dug over in gardening operations, and they should be destroyed. The moths may be attracted by light, or by "sugaring," and should be caught and killed.
Potherbs are also frequently damaged by hairy larvae. Some account of these will be found under Tiger Moths (which see).