About Ichneutica insignis
George Hudson described the eggs of Ichneutica insignis as semi-globose, considerably flattened both above and beneath. A number of branching ribs radiate out from the micropyle, with the spaces between the ribs having slight transverse ribbing. The egg is pale green when new, and darkens to brown in the centre as the enclosed embryo develops. Newly hatched larvae are pale brown with numerous black warts that bear black bristles. After around twelve days, larvae become pale green, and lateral and subdorsal lines begin to appear after moulting. Hudson described the fully mature larva of this species as follows: A full-grown larva is pale greenish-brown, with a yellowish tone on the ventral surface. Its lateral lines are made up of a series of black markings near the posterior margin of each segment. The subdorsal lines are formed by four oblique black marks on each side of the four posterior segments of the larva. The area between these lines is heavily clouded with yellowish green or pink, and the species tends to diverge into separate pink and green varieties. The anal segment is dull yellow, and the head is brown with two black stripes and several black dots. Francis Walker described the adults of this species as follows: Both males and females are ferruginous-cinereous. The palpi are stout, obliquely ascending, and do not reach as high as the vertex; the third joint is conical, very minute, and no more than one-eighth the length of the second joint. Male antennae are very slightly pectinated along their full two-thirds length. The fore tegulae of the thorax have a curved black band on each side. The abdomen is brownish, extends slightly beyond the hind wings, has crests toward the base, is reddish on each side, and bears a small reddish apical tuft in males. Fore wings are variegated with glaucous-cinereous and blackish; the glaucous-cinereous hue forms an irregular, interrupted submarginal band that extends along the costa in three streaks to the exterior border. There are some zigzag black lines on the fore wings, along with orbicular and reniform marks of the typical shape. The orbicular mark is bordered with pale cinereous, and the reniform mark is entirely pale cinereous. The wing fringe has longitudinal pale cinereous streaks. Hind wings are brown. Body length ranges from 7 to 8 lines, and wing length ranges from 18 to 20 lines. I. insignis is variable in appearance, and as a result is difficult to distinguish from its close relatives I. skelloni and I. plena. The pectinations on the antennae of male I. insignis are longer than those of I. skelloni. Many specimens of I. insignis often have a "distinct whitish suffusion" on the forewing dorsum that is considered a diagnostic feature. This marking is absent in I. plena, and while I. skelloni may have a similar pale marking, it is not whitish in colour. This species is found throughout New Zealand. Although it occurs in a wide range of habitats across the country, it is scarce or entirely absent from inland tussock grassland sites. Larvae hatch from eggs after approximately two weeks. I. insignis larvae feed on a variety of plants, and have been recorded feeding on Trifolium pratense.
