We shall briefly notice a few members of each of the three genera.
The Turnip Moth (Agrotis Segetum)
This is another of those destructive insects that attack vegetable and flower gardens, often doing so much damage to our crops as to become quite a nuisance to cultivators.
The moth is decidedly dingy. Its fore wings are brown, clouded with a darker tint. The hind wings are almost white, sometimes with a brown hind margin.
In June it lays its eggs on the stems of young plants, generally very close to the ground. As soon as the young caterpillars emerge they commence feeding on the lower parts of the stems, or burrowing deeply into the larger succulent roots. When the larvæ have completed their work of destruction in this way, they change to brown chrysalides in the ground. Some undergo this change in October, and shortly after give rise to a second brood of moths; but most of them remain in the caterpillar state throughout the winter, and, contrary to the general rule with hybernating larvæ, continue to feed almost throughout the winter months, and change to the chrysalis in the following May.
The caterpillar grows to a large size. It is of a greyish or greenish colour, with a paler line on the back, a light brown line on each side of this, black spots between these lines, and black spiracles.
The Heart and Dart (Agrotis Exclamationis)
The destructive work of Segetum is assisted by similar operations of the Heart and Dart, the larva of which feeds voraciously on the roots of several of our cultivated vegetables, though the present species does not entirely confine its ravages to the farmer's crops, but attacks the roots of many low-growing herbs.