The pupa is enclosed in a slight cocoon situated about two inches below the surface of the ground. Those larvæ which become full grown in the autumn remain as pupæ during the winter, but the summer broods only remain in the pupa state a few weeks.
The perfect insect appears from November till March. It has a great partiality for resting with outspread wings on the walls of sheds and outhouses, where it is frequently noticed by the most casual observer. It is very common in most situations, and may be taken in large numbers at sugar, light, or blossoms, during the whole of the summer. Its extreme abundance and great variability, in both the larval and imago states, would render it a good subject for a series of experiments, resembling those conducted by Messrs. Poulton and Merrifield on several allied European species.
SELIDOSEMA PANAGRATA, Walk.
(Scotosia panagrata, Walk. 1360. Angerona menanaria, Walk. 1500. Epirrhanthis (?) antipodaria, Feld. cxxvi. 3. Hyperythra desiccata, Butl., Cist. Ent. ii. 495. Hyperythra arenacea, Butl., Cist. Ent. ii. 495. Barsine panagrata, Meyr., Trans. N. Z. Inst. xvi. 100.)
(Plate [IX]., figs. 25, 26, 27, and 28 ♂ varieties, 29 and 30 ♀ ditto.)
This species is very common, and generally distributed throughout the country. It has occurred as far south as Stewart Island.
The expansion of the wings is from 1½ to 1¾ inches. The fore-wings of the male vary from pale yellowish-white to rich brown or dark brownish-black; there is a jagged transverse line near the base; a large black or white spot in the middle of the wing; a doubly curved transverse line beyond the middle, then a very jagged transverse line, followed by several paler markings, and an obscure line parallel with the termen. The hind-wings are paler in colour; there is a slightly curved transverse line near the base; a jagged line near the middle, and a very faint line beyond the middle. The termen of both fore- and hind-wings is slightly indented. The female varies from pale ochreous to dark slate-colour; the markings resemble those of the male, but the termen of the wings is more indented.
This species is so extremely variable that a more detailed description would be useless; its numerous forms may, however, be at once recognised by the unbroken jagged transverse lines of both fore- and hind-wings.
The larva is quite as variable as the perfect insect. When very young it is bright green, with a conspicuous white dorsal line; as age advances the caterpillar becomes dark olive-brown, sometimes striped with paler brown or green, whilst many specimens retain the green colouring throughout the whole of their lives. The favourite food-plant is the kawa-kawa (Piper excelsum), which the larvæ voraciously devour, thus causing the riddled appearance which the leaves of that plant almost invariably present. These larvæ often select a forked twig to rest in, where they lie curled round, with the head and tail close together. Other food-plants are Aristotelia racemosa and Myrtus bullata. Those caterpillars found on the latter plant are strongly tinged with pink, and are consequently very inconspicuous amongst the young shoots, where they generally feed. The burrows of the larvæ of Hepialus virescens are frequently utilised by the caterpillars, which feed on the Aristotelia, as convenient retreats during the winter. When full-grown these caterpillars descend to the ground and construct loose cocoons of silk and earth on the under sides of fallen leaves. The moth usually emerges in about a month's time, but the autumnal larvæ either hibernate or remain in the pupa state throughout the winter.
The perfect insect appears from October till April. It frequents forest and is extremely common. It also occurs in great abundance on the white rata blossoms in the autumn, and specimens may be occasionally seen even in the depth of winter.