Lepidoptera The Small Tortoiseshell Butterfly – Vanessa Urtica
Urtica (Plate III, fig. 9) may be distinguished from Polychloros by the absence of the black spot in the anal angle of the fore wings of the latter. It has also a white spot near the tip of each fore wing-between the black border and the first black costal patch. The whole of the base of the hind wing is also black, and the ground colour is decidedly brighter.
It is one of the commonest of all British butterflies, and is to be found more or less abundantly in nearly all parts of the British Isles.
The hybernated perfect insects come out early in the spring, and lay their eggs in close irregular clusters on nettles (Urtica dioica and U. urens). Shortly after the gregarious caterpillars may be found on these plants in dense masses. They change to the chrysalis state about the end of May, and from this time there is a continuous succession of butterflies till the end of the summer.
The later specimens, which do not emerge till September or October, spend only a short time on the wing, and then hybernate till the spring, giving rise to the first brood of the following season.
The caterpillar of this species is black above and greyish beneath. It is thickly covered with yellow dots, which are so close together on the back as to form two yellowish stripes, separated only by a fine black line. There are also two yellowish stripes along each side; and the body, as with the rest of this genus, is spiny, the spines in this case being black or very dark green.
The chrysalis is brownish, and spotted with burnished gold in variable quantity-sometimes so plentifully as to cover the greater part of the surface.