ASTHENA SCHISTARIA, Walk.
(Acidalia schistaria, Walk. 782. Asthena subpurpureata, Walk. 1588. Acidalia tuhuata, Feld. cxxviii. 5. Asthena schistaria, Meyr., Trans. N. Z. Inst. xvi. 69.)
(Plate [VI]., figs. 39, 40 ♂, 41, 42 ♀ varieties.)
This pretty species is common, and generally distributed throughout the country.
The expansion of the wings is nearly an inch. All the wings vary from very pale brown to rather dull purplish-brown; there are numerous jagged, darker, transverse lines forming several more or less distinct bands. The first of these bands extends from the base to about one-eighth; the second, composed of only two or three lines, is situated at about one-third; the third extends from three-fourths to about five-eighths; there are in addition, numerous very fine, wavy lines near the termen. The spaces between these bands are paler, and in some specimens the bands are very conspicuous, whilst in others they are hardly perceptible. One specimen in my collection (Plate [VI]., fig. 39) has a very broad chocolate-brown band across the middle of both pairs of wings, the remaining portions being unusually pale in colour. There is always a dark brown dot in the centre of each wing, and a series of very fine dots on the termen.
The larva, which feeds on Manuka (Leptospermum), is very ornamental. Its general colour is light green, with black dorsal and lateral stripes, and a series of diagonal markings bordered with crimson; the legs and prolegs are also crimson, and the segments are divided by brilliant yellow rings, a white line extending down each side of the larva.
This caterpillar is difficult to find, as it remains closely concealed amongst the dense Manuka foliage, from which it can be dislodged only by vigorous and continued beating. The larvæ allow themselves to fall a short distance, hanging suspended by a silken thread, which they rapidly ascend when the danger is past.
The pupa is enclosed in a slight cocoon about one inch below the surface of the earth.
The perfect insect appears from October till April. It is very common in most situations where its food-plant is found and, owing to its pale colour, is readily seen when flying in the evening twilight. Specimens may also be taken in the daytime resting with outspread wings on the trunks of trees and on fences, where they are much more easily detected than many other species.
Mr. Meyrick thinks that this insect will also be found in Australia.