This insect varies slightly in size, especially in the female. The larva is dull greyish-brown, with the subdorsal and lateral lines darker. It feeds on honeysuckle during the summer months.
The pupa state is spent in the earth.
The moth is very irregular in its appearance. I have captured specimens in January, February, March, April, July and September. It appears to pass the winter in both the pupa and imago states. It is very partial to light, and in consequence often enters houses.
MELANCHRA PRIONISTIS, Meyr.
(Mamestra prionistis, Meyr., Trans. N. Z. Inst. xix. 27.)
(Plate [V]., fig. 21 ♂.)
This species is common at Wellington in the North Island. In the South Island it has been taken at Rakaia.
The expansion of the wings of the male is 1⅝ inches, of the female 1¾ inches. The fore-wings are rather pale yellowish-brown, with numerous irregular longitudinal grey streaks; there are several very obscure jagged transverse lines, and the stigmata are almost invisible; a very broad blackish longitudinal band is situated on the dorsum. The hind-wings are brownish-grey; the cilia are grey tipped with white. The head and thorax are grey tinged with yellowish-brown; there is a conspicuous blackish streak on each side of the thorax.
In this species the dorsal band is often considerably paler, but otherwise there is no variation.
The perfect insect appears from November till April. It comes freely to sugar, and occasionally to light. It is also sometimes met with at rest on trees in the daytime, where its colouring is protective. I have noticed that this moth is much commoner in some years than in others.