Part 14

Abundant among various blossoms during the latter end of summer, being one of the last of the Noctuæ to disappear in the autumn.

The larva probably feeds on grasses, but I have not yet met with it.

The illustration (Fig. 2) is taken from the male insect, the female differing only in having her abdomen rounded at the tip, a sexual distinction which holds good throughout the family.

Family NOCTUIDÆ.

Erana graminosa (Plate X., fig. 5, 5a larva).

This beautiful insect occurs commonly on the white rata blossoms (Metrosideros scandens) round Wellington during March and April, at which time it may be readily taken just after dark with a lantern and killing-bottle. The larva (Fig. 5a) feeds on the mahoe (Melicytus ramiflorus) in the spring and autumn. It remains concealed in crevices in the bark during the day, not infrequently selecting the deserted burrows of wood-boring beetles as a secure retreat from its enemies. When full grown it is olive-green, the colour being lighter on the ventral surface and between the segments. A row of ill-defined, feathery, black markings extends down the back and sides and there are also two tolerably conspicuous ochreish spots on every segment except the last. The head, legs, and prolegs are reddish-yellow, and the whole insect is more or less spotted with black. Younger larvæ differ in being of a light yellowish-green, with very pale yellow dorsal and lateral lines. A row of black warts, emitting a few bristles, extend round each of the segments, while the head is pale ochreous with a few black dots.

When full-grown this larva descends to the ground, and {79}forms a slight cocoon in the earth round the roots of the tree, where it is transformed into a very stout, ruddy-brown-coloured pupa, somewhat paler on the wing-cases. The moth emerges in two or three months' time. Its colouring renders it so inconspicuous amongst moss that I have frequently lifted a handful of the latter out of the breeding cage, and only discovered that the insects had emerged by their falling from the moss on to the table. A very noticeable peculiarity in this species is the presence of a fringe of long hairs in a fold on the anterior margin of the fore-wing. This organ emits a fragrant perfume, and is confined to the male sex (Fig. 5). Only one or two other instances of this kind are at present known among the New Zealand moths.

Family NOCTUIDÆ.

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 {80}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 {81}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.

Heliothis armigera (Plate X., fig. 4, 4a larva).

This conspicuous insect occurs in great abundance during certain seasons, but is very irregular in its appearance, it frequently happening that only two or three specimens are noticed in a whole year. It is generally seen flying in the daytime, when it delights to suck honey from the flowers of the Scotch thistle, a plant which much overruns the forest lands when first cleared. The larva (Fig. 4a) is a very handsome caterpillar, of a dark brownish black colour, ornamented with yellow subdorsal and lateral lines and numerous streaks and dots of the same hue. The ventral surface is a rich yellowish brown, and the subventral line {82}white, the spiracles being white with black rings; a reddish blotch also adorns each of the three thoracic segments. It feeds voraciously on geraniums, tomatoes, peas, and many other garden plants, where it often commits the most serious ravages. About the end of April it is full-grown, when it descends to the ground and buries itself two or three inches below the surface. In this situation it is shortly transformed into a pupa, remaining in that state until the following summer, when the moth appears. The sexes of this insect differ considerably, the male having the fore-wings of a ruddy-brown colour, sometimes inclining to orange, while in the female they are pale ochreish; both sexes are, however, subject to considerable variation, and the figure (4) is taken from a rather dark male specimen.

Family NOCTUIDÆ.

Plusia eriosoma (Plate X., fig. 8, 8a larva).

An abundant species round Nelson, where almost any number may be taken hovering over flowers on a still summer's evening. In Wellington it occurs occasionally. The larva (Fig. 8a) is a pseudo-geometer, having twelve legs, and thus showing a strong affinity with the next family. In colour it is pale green, darker on the dorsal surface than elsewhere. A white line runs down each side, and the whole insect is covered with black dots and bristles. The colouring of different individuals varies in intensity, and a fainter white line, above the usual one, exists in some specimens. It feeds on beans, geraniums, and many other imported plants, and is doing much good in the Nelson gardens by the havoc which it is committing among the Scotch thistles--weeds equally injurious to the agriculturalist and the gardener, not only crowding out useful plants, but rapidly exhausting the soil in which they grow. Formerly this insect must have fed exclusively on the New Zealand {83}nightshade (Solanum aviculare), on which plant it may still be occasionally found in the forest, where no imported species are available, but, like many other caterpillars in this country, it is forsaking the native vegetation for the European. When full-grown, this larva spins a slight cocoon of white silk, which is generally placed between two leaves. The pupa is of a shiny black colour, the membrane between the segments being reddish-brown. The moth emerges in about three weeks' time. The figure (8) is taken from a female insect, the male being readily distinguishable by two large tufts of hair situated at the end of his body and often very conspicuous. In some cases the wings of the female are considerably lighter than in the illustration, but otherwise the species does not seem to vary. It is the New Zealand representative of the English "Silver Y Moth" (P. gamma), no doubt familiar to many of my readers.

Family GEOMETRIDÆ.

Declana floccosa (Plate XI., fig. 1, 1a larva).

I have started the Geometridæ with Declana because it exhibits a great many more points in common with the Noctuidæ than does the genus Acidalia, which latter is placed at the head of the Geometridæ by some modern Lepidopterists, chiefly, I believe, on account of neuration, a character which if taken alone cannot but produce the most unnatural divisions. The present insect is one of the commonest of the genus, and may often be observed throughout the whole summer resting on the sheltered sides of trees and fences, occasional stragglers being met with as late as the end of May. Its larva is a pseudo-geometer possessing twelve legs (Fig. 1a), and thus almost exactly resembling the caterpillars of the genus Catocala, belonging to the Noctuidæ; the curious filaments on each side of the insect making this likeness still more complete. It feeds {84}on the "New Zealand currant" (A. racemosa), from which, individuals can be occasionally beaten during the spring and early summer. They are almost impossible to find by searching in the ordinary way, from a habit they possess of clinging firmly to the twigs, which they exactly imitate in colour. When full-grown this caterpillar constructs a small cocoon just below the ground, where it is transformed into a robust-looking pupa, from which the moth emerges in a month or six weeks' time. The sexes of this species may be readily distinguished, the male (Fig. 1) having the antennæ slightly pectinated, while those of the female are quite simple, and her body much more robust. The moth drawn at Fig. 1b has been reared from larvæ exactly resembling those of the present insect, of which it is consequently now known to be only an extreme variety. It was formerly ranked as a distinct species under the name of Declana junctilinea.

Family GEOMETRIDÆ.

Chalastra pelurgata (Plate XI., fig. 2 , 2a , 2b larva).