Cardamines is a single-brooded insect, and is essentially a creature of the spring, at which time it may be found in abundance in lanes, meadows, and clearings in woods throughout the British Isles. Its flight is so light and airy that even the female may easily be distinguished from other Whites when on the wing, while the brilliant orange of the male, intensified by the bright rays of the spring sun, may be identified at some considerable distance.
The food plants of Cardamines include the cuckoo-flower (Cardamine pratensis) and the bitter cress (C. impatiens), after which the insect is named, also water-cress (Nasturtium officinale), winter cress (Barbarea vulgaris), rock cress (Arabis perfoliata), hedge mustard (Sisymbrium officinale), Jack-by-the-hedge (S. Alliaria), wild mustard (Brassica Sinapis), &c., and the eggs of the butterfly may be found on these during May and June.
The caterpillar ([Plate VIII], fig. 2) is green, with a white stripe on each side, and its body is covered with short hair. In July it is
fully grown, and ascends a stem of the food plant to prepare itself for its long winter sleep.
The chrysalis ([Plate VIII], fig. 8) is a very peculiar object. Both ends are much elongated and sharply pointed; and the foremost extremity stands out at an angle with the stem to which it is attached.
This butterfly should be looked for during April and May, but in mild seasons it may often be met with in March.
The Wood White (Leucophasia Sinapis)
The distinguishing feature of this butterfly (see [Plate II], fig. 1) is the extreme lightness and delicacy of its build. Its wings are narrow, and rounded at the tips; and the only mark to relieve the white ground of the upper side is a squarish blotch at the tip of the fore wing, and even this is either very indistinct or entirely absent in the female. The under surface is clouded with a pale greenish tint.
This insect may be looked for in May and again in August, in paths and clearings in woods, where it moves along with a slow but steady flight, hardly ever seeming to rest for a moment. It is not by any means a common butterfly, but is very widely distributed, and sometimes appears in considerable numbers in certain favoured spots. Among the localities recorded may be mentioned Torquay, Exeter, Plymouth, South Dorset, New Forest, Reading, Darent Woods, Morecambe Bay, Haslemere, Windermere, &c.
The caterpillar is of a beautiful green colour, and is covered with short whitish hairs. A darker green stripe runs down the middle of the back, and a bright yellow stripe along each side. Its food plants are the tufted vetch (Vicia Cracca), bird's-foot trefoil (Lotus corniculatus and L. pilosus), bitter vetch (Lathyrus tuberosus), and the everlasting pea (L. sylvestris).