Mamestra mutans (Plate [X]., fig. 7, 7a larva, 7b pupa).
This extremely abundant species occurs almost without intermission during the whole of the year. The sluggish larva (7a) feeds on plantain, and is best obtained by overturning logs and stones, when it may be discovered among the grass and other plants growing round their edge. Its head is pale green, with two broad black stripes, and is clothed with numerous short bristles; the four succeeding segments are of a ruddy-brown colour, considerably wrinkled, the remainder being light green, suffused with a dull, pinkish hue towards the dorsal surface. The markings consist of a triangular black spot on each side of the second to eighth abdominal segments, and a cloudy lateral line of the same colour; the legs and prolegs being pale green, and the whole insect more or less marbled with black. This description and the figure on Plate [X]. exhibit the usual peculiarities of the larva, but in some individuals the markings there indicated are quite obsolete, and the insect is of an almost uniform pale-green colour. When mature, this caterpillar sometimes constructs a slight cocoon amongst moss, on fallen trees, but more often buries itself in the usual manner, the moth appearing in a few weeks' time. Nearly all pupæ collected at random in New Zealand will be found to give rise to either this species or the one which immediately follows (Mamestra composita). The perfect insect is most abundant in the spring and early summer, but may be found fluttering round lamps on any mild night throughout the year. The sexes differ considerably: the female is greyish white, with faint brown markings, while the male is dull reddish-brown, with the markings considerably darker (Fig. 7). His antennæ are also slightly pectinated, those of the female being quite simple.
Family Noctuidæ.
Mamestra composita (Plate [X]., fig. 3, 3a larva).
Very common during the spring and autumn in all open situations.
Its pretty larva (Fig. 3a) feeds on various grasses, and threatens in time to do considerable damage to pastures. The head and dorsal surface of the first segment are dark shining green, with one or two obscure white markings; the rest of the body is ornamented with a number of parallel brown, white, and orange lines, which render the larva very inconspicuous when amongst the grass. Sometimes it occurs in great numbers, nearly every blade of grass having its caterpillar; in fact this was almost the case in the Wairarapa valley in the summer of 1886, when the larvæ must have produced a marked effect on the paddocks. When full-grown this caterpillar changes into a light chestnut-brown pupa, which lies on the surface of the ground amongst the vegetable refuse. The perfect insect appears in about a month's time, and if the evening be mild may be seen flying with great rapidity at dusk; it may also be readily captured at light. The figure (3) represents the male insect, the female differing only in her simple antennæ.
Family Noctuidæ.
Mamestra ustistriga (Plate [X]., fig. 6 ♂).
This handsome insect is rather uncertain in its appearance, but is occasionally taken quite unexpectedly at rest on tree-trunks or palings in the daytime. Specimens may also be captured while feeding on the white rata blossoms early in March, where they occasionally occur among the hosts of other Noctuæ. The larva, which feeds on the honeysuckle, is of a pale brown colour, with two obscure darker lines on each side, the under-surface being light slate-colour. The pupa state is spent in the ground, and many fine specimens may be reared from chrysalids picked up while gardening, &c. The sexes of this insect differ considerably in colour: the male is of a pinkish grey with black markings, while the female is of a uniform pale grey, and considerably smaller.
Family Noctuidæ.