This species is extremely variable, but may always be recognised by its greenish tinge, and the absence of indentations on the termen of both fore- and hind-wings.
The larva, according to Mr. Purdie, is about ¾ inch long; dull green with darker longitudinal striations. It may be beaten from New Zealand broom (Carmichælia) in February. There must be some other commoner food-plant, as the moth is found in many localities where the New Zealand broom does not occur.
The perfect insect appears from November till March, and is generally very abundant in all wooded districts. It is also common in birch forests on the mountain sides, where it may be taken at altitudes of from 3,000 to 4,000 feet above the sea-level. In the lowlands I have observed as many as half a dozen specimens on a single tree-trunk. Whilst resting in this situation they are very inconspicuous, the colouring of the fore-wings harmonizing perfectly with the insect's surroundings, and the pale-coloured hind-wings being then entirely concealed by the upper pair. In connection with this fact it is very interesting to notice that in all those cases where the hind-wings are exposed to view during repose, they are protectively coloured in a similar manner to the fore-wings. It will be observed that the two following species of Selidosema exhibit protective colouring on both pairs of wings, these being invariably exposed when the insects are at rest.
SELIDOSEMA DEJECTARIA.
(Boarmia dejectaria, Walk. 394. Boarmia attracta, Walk. 394. Boarmia exprompta, Walk. 395. Tephrosia patularia, Walk. 422; Butl., Cat., pl. iii. 8. Tephrosia scriptaria, Walk. 422. Scotosia erebinata, Walk. 1358. Scotosia stigmaticata, Walk. 1359. Scotosia lignosata, Walk. 1361. Gnophos pannularia, Gn., E. M. M. v. 42. Scotopteryx maoriata, Feld. cxxvi. 4. Hemerophila (?) sulpitiata, Feld. cxxvi. 7. Hemerophila caprimulgata, Feld. cxxvi. 12. Boarmia dejectaria, Meyr., Trans. N. Z. Inst. xvi. 100.)
(Plate [IX]., figs. 19, 20, 21 and 22 ♂ varieties, 23 and 24 ♀ ditto; Plate [III]., fig. 12, larva.)
This large insect is very common, and generally distributed throughout the country.
The expansion of the wings is from 1½ to 2 inches. The fore-wings vary from pale ochreous to very dark rich brown; there is an oblique transverse line near the base, often enclosing a darker basal area; a small dark brown spot in the middle of the wing surrounded by a ring; a very oblique, wavy, transverse line beyond the middle, often double towards the dorsum, and several irregular markings on the termen; there is often a white spot on the middle of the termen, and a pale blotch on the apex of the wing. The hind-wings resemble the fore-wings in colour; there are two obscure transverse lines near the base; generally forming a dark basal area; a wavy line near the middle, and a strongly shaded line near the termen. The termen of both the wings is indented, the depth of the indentations varying greatly in different specimens.
This insect is very variable, but its large size and oblique transverse lines suffice to distinguish it from any of the other allied species.
The larva feeds on a great variety of plants, mahoe (Melicytus ramiflorus), white rata (Metrosideros scandens), Solanum aviculare, fuchsia (Fuchsia excorticata), and Pennantia corymbosa being amongst the number. The caterpillar may often be recognised by a large hump, which is situated on each side of the third segment. Its colouring appears to be so entirely influenced by its surroundings that a description is impossible. For instance, larvæ taken from the pale green foliage of the mahoe resemble in colour the twigs of that plant; others captured feeding on the white rata are dark reddish-brown, those from Solanum aviculare are purplish slate-colour, whilst those from the fuchsia are pale olive-green tinged with brown, like the sprouting twigs.