(Plate [IV]., fig. 32.)
Apparently common in the Canterbury district, where it has been taken at Christchurch and Mount Hutt. In the North Island it has occurred in the neighbourhood of Wellington.
It resembles Melanchra insignis in every respect except that the head, thorax, and fore-wings are entirely suffused with green; there is no central black streak at the base, and the orbicular, reniform, and claviform spots are smaller.
It varies a little in the intensity of the green colouring.
The eggs are deposited early in November. At first they are white in colour, but soon become dull brown, with two concentric circular markings. The young larva closely resembles that of the Melanchra insignis, but is much more sluggish. It feeds on grasses and other low plants.
In about six weeks' time it is full grown, when it still resembles the caterpillar of Melanchra insignis, except that its colouring is considerably darker, and a number of rust-red spots are situated on the subdorsal line. This larva also appears to spend the daytime underground, only coming abroad in the evening to feed. The pupa is concealed in the earth.
The perfect insect may be occasionally found at rest on tree-trunks in the forest, where it is very hard to discover, as it almost exactly resembles a little patch of moss or lichen. Specimens are sometimes noticed in the middle of winter, so there is little doubt that this species hibernates. It occurs in spring as late as November, and as the pupæ emerge during the latter end of January the insect is about for most of the year.
MELANCHRA LITHIAS, Meyr.
(Mamestra lithias, Meyr., Trans. N. Z. Inst. xix. 17.)
(Plate [IV]., fig. 33.)