This species is rather variable. The spaces between the darker bands on the fore-wings are usually green, but in some specimens this is partially or wholly replaced by pale yellowish-brown. The dark bands also vary considerably in width and distinctness, and in many specimens the central band is entirely divided by a conspicuous pale brown or green transverse space.
The larva, according to Mr. Purdie, is about 1 inch long, cylindrical. Back a dull deep green; lateral stripe reddish-white, edged below with a darker colour; ventral side lighter green, with four parallel white or yellow lines close together, extending from the forelegs to the prolegs. Outer side of prolegs white. There are traces of a median dorsal stripe of brownish-red on the anal segments. Beaten from _Coprosma_. Found in January. Mr. Purdie states that he is not quite certain as to the identification of the species, as the median belt of the fore-wings is much more distinctly defined, and the colour is a duller green than is usual in _H. similata_.
The perfect insect appears from November till March. It is generally found resting on moss-covered tree-trunks, where its colouring affords it a most efficient protection from enemies.
(_Cidaria callichlora_, Butl., Cist. Ent. ii. 509; Meyr., Trans. N. Z. Inst. xvi. 76.)
This beautiful insect has occurred at Wellington in the North Island, and at Christchurch and Invercargill in the South Island.
The expansion of the wings is about 1 inch. _The fore-wings are bright green, with three very distinct wavy black transverse lines_; the first near the base, the second a little before the middle, and the third considerably beyond the middle; between these there is a number of fainter fine wavy lines. The hind-wings are whitish with several very faint wavy transverse lines; the cilia of all the wings are dull yellowish-brown.
The perfect insect appears in January, February, and March. Described and figured from a specimen in Mr. Fereday's collection.
(_Melanthia arida_, Butl., Cist. Ent. ii. 505. _Cidaria chaotica_, Meyr., Trans. N. Z. Inst. xvi. 76. _Cidaria arida_, Meyr., ib. xvii. 64.)
This species has occurred in the South Island at Akaroa, Mount Hutt, Arthur's Pass, and Dunedin.