Part 17

This insect is so extremely variable that I have given descriptions of a few of the principal varieties below; all these forms may, however, be connected by specimens exhibiting every intermediate gradation both in colour and in markings.

1. Fore-wings with several large brown spots near the middle.

2. Fore-wings covered with numerous black spots (formerly known as _Declana nigrosparsa_) (fig. 47).

3. Fore-wings with two more or less conspicuous curved black or brown lines from costa to dorsum (figs. 41, 42, and 44).

4. Fore-wings with these transverse lines joined by two others running parallel to dorsum and costa.

5. Fore-wings with transverse lines and black spots (fig. 43).

6. Fore-wings diffused with dark greyish-black, except two broad bands of the original light colour extending from costa to dorsum; hind-wings darker than usual (fig. 45).

7. Fore-wings with a dark brown central band; hind-wings clouded with dark brown towards termen, with a faint curved transverse line near the middle (figs. 39 and 40).

All these varieties occasionally have tufts of orange-yellow scales on both the wings and on the body, and they also vary in other minor particulars (fig. 46).

The egg of this insect when first laid is oval in shape and light green in colour, becoming bronzy a few days before the emergence of the larva. The young larva is very attenuated, with only ten legs. {97}Its colour is pale yellow striped with brownish-pink near the segmental divisions. It is very active, and does not devour the egg-shell after emergence.

The full-grown larva has the body much flattened underneath. In colour it is pale brownish-pink, with numerous irregular darker markings, which in some specimens almost form two broad subdorsal lines. The under surface of the larva is pale green. There is a series of fleshy filaments of a pinkish-brown colour along each side of the insect, and an extra pair of prolegs on the ninth segment.

This caterpillar is, however, very variable, its colouring appearing to depend largely on its surroundings. The favourite food-plants are _Leptospermum ericoides_ and _Aristotelia racemosa_. The larvæ found on the former plant are usually pale yellowish-brown, whilst those from the latter are much darker brown, often mottled with grey like the stems of the _Aristotelia_. A specimen I once found on a mountain beech (_Fagus cliffortioides_), the gnarled stem and branches of which were covered with grey lichens and mosses, was mottled with the most beautiful shades of greenish-grey. These larval varieties are very interesting, and in order to test the direct influence of food on the colouring of the larvæ, I once divided a batch of eggs deposited by a single female into two equal parts, and fed one half on _Aristotelia_, and the other half on _Leptospermum_. The differences in colouring between the two lots of larvæ thus treated were, however, of the most trivial description. This somewhat surprised me at first, as I had previously observed quite distinct varieties on each plant, when found in a state of nature. Hence I am now disposed to think that these differences have been brought about gradually, by natural selection acting on larvæ feeding on the same plant for a large number of generations. By this means a sufficient amount of variation might be accumulated, to cause the closest possible approximation in colouring to the stems of the several food-plants. It is also noteworthy that many of these food-plants grow in widely dissimilar localities, so that the free inter-breeding of insects dependent on them would not be likely to occur, and thus the peculiarities of colouring adapted to the stems of each food-plant would not be disturbed by the effects of inter-breeding.

In connection with the foregoing experiment it is also interesting to observe, that the specimens fed on _Aristotelia_ matured much more rapidly than those on _Leptospermum_; the former plant evidently being the more nourishing food for the larvæ. Also that out of the batch fed on _Aristotelia_ 28 became moths, of which 12 were males and 16 females; whilst out of those fed on _Leptospermum_ only 24 became moths, of which 15 were males and 9 females. In all other respects, excepting food-plant, the two lots of larvæ were subjected to identical treatment.

During the day this larva rests quietly attached to the stem of its food-plant, where it is very difficult to detect, as the filaments so closely embrace the twig or tree-trunk that the whole insect exactly resembles a swelling in the stem.

The pupa of _D. floccosa_ is enclosed in a loose cocoon on the surface of the ground.

The perfect insect appears about September, and continues in more or less abundance until the end of April. There are most likely several broods in a season, and, as we frequently meet with specimens of the moth on mild days in the middle of winter, it probably also hibernates.

This insect is usually observed at rest on fences and tree-trunks, where its grey mottled colouring causes it to closely resemble a patch of lichen.

{98}DECLANA JUNCTILINEA, Feld.

(Plate X., fig. 37 [M], 38 [F].)

This species has occurred occasionally in the Wellington Botanical Gardens. It is no doubt found elsewhere, but I cannot give any other localities with certainty.

The expansion of the wings of the male is 1¼ inches, of the female 1-3/8 inches. The fore-wings of the male are pale yellowish-brown, with two indistinct, irregular, transverse darker lines near the base, a conspicuous curved line a little beyond the middle, followed by a blackish patch; _there is a series of very fine parallel oblique brown stripes on the costa_, and several series of curved, blackish marks near the termen, and on the central portions of the wing. The fore-wings of the female are much greyer, with a conspicuous, irregular, white streak from the apex towards the dorsum, the central portions of the wing are white, and, with the exception of the fine, oblique costal stripes, the other markings of the male are usually absent. The hind-wings of both sexes are dull ochreous. The strongly pectinated antennæ of the male, and the oblique costal markings of both sexes, will at once distinguish this species from any of the varieties of _Declana floccosa_.

This moth varies in the intensity of the markings, which in some specimens are very indistinct.

The perfect insect appears from November till March. It is generally captured on blossoms in the evening.

DECLANA HERMIONE, n. sp.

(Plate X., fig. 36.)

A single specimen of this very handsome insect was captured at Khandallah near Wellington.

The expansion of the wings is 1¼ inches. _The fore-wings are bright purplish-brown, clouded with silvery-white towards the middle and on the termen_; there is a very fine oblique chocolate-brown mark at the base, a broad broken transverse band at about one-eighth; a fine curved transverse line at about three-fourths, shaded towards the termen; there are four wavy brown marks on the termen inclining obliquely upwards towards the costa; the termen itself is narrowly edged with chocolate-brown. The cilia are silvery mixed with brown; the termen is very strongly bowed. The hind-wings are grey, shaded with purplish-grey towards the termen; the cilia are grey.

The type specimen was captured at sugar in November.

DECLANA GRISEATA, n. sp.

(Plate X., fig. 32 [F].)

This species has occurred at Wellington in the North Island, and at Lake Wakatipu in the South Island.

The expansion of the wings of the male is 1-1/8 inches, of the female 1-3/8 inches. _The fore-wings are dull slaty-grey, with a slightly paler central band_; there is a fine oblique wavy transverse line at about one-fourth, another at about one-half, and indications of a third at about three-fourths; _numerous minute black streaks are thickly scattered over the wing, especially near the base and the termen_; the outline of the termen is very slightly scalloped. The hind-wings are pale grey, darker near the termen. The body is very dark slaty-grey. _The antennæ of the male are not bi-pectinated._

The perfect insect appears in January, and is attracted by light. It is a scarce species.

DECLANA NIVEATA, Butl.

(_Declana niveata_, Butl., Cist. Ent. ii. 500. _Atossa niveata_, Meyr., Trans. N. Z. Inst. xvi. 104.)

This species has occurred at Dunedin, in the South Island.

"The expansion of the wings of the male is 30 mm. (about 1¼ inches). Fore-wings elongate-triangular, costa somewhat sinuate, termen rounded, dentate; dull white, faintly irrorated with grey; costa marked with short indistinct dark grey direct strigulæ; an irregular line towards base, and another twice angulated about two-thirds, obscurely indicated by dark grey scales; some scattered {99}dark grey strigulæ before termen. Hind-wings moderate, termen crenate, angularly projecting in middle; wholly white.

"I took one fine specimen at rest on a tree-trunk near Dunedin, in February."--(Meyrick.)

Family 6.--SPHINGIDÆ.

"Head with dense appressed hairs. Ocelli absent. Eyes glabrous. Antennæ thickened towards middle or posteriorly, in male ciliated with partial whorls. Labial palpi moderate, ascending, with dense projecting scales. Thorax densely hairy beneath. Femora densely hairy. Fore-wings with vein 1_b_ furcate, 6 out of 8, 9 absent (rarely present in exceptional individuals). Hind-wings with veins 3 and 4 approximated at base, 5 from middle of transverse vein, parallel to 4, 6 and 7 connate or stalked, 8 connected by oblique bar with margin of cell before middle, more or less approximated to 7 near beyond cell." (Plate I., figs. 12 and 13, neuration of _Deilephila_ [after Meyrick].)

"This family is generally distributed, but is most plentiful in the tropics. The imagos are usually large insects, with stout, heavy bodies, elongate-triangular fore-wings with very oblique termen, and relatively small hind-wings; the wing muscles are very strong, and the flight exceptionally powerful. Ovum spheroidal, smooth. Larva stout, usually with an oblique, projecting anal horn, anterior segments sometimes retractile or raised in repose. Pupa subterranean."--(Meyrick.)

Only one genus is represented in New Zealand, viz., _Sphinx_.

Genus 1.--SPHINX.

"Tongue strongly developed. Antennæ less than one-half, gradually thickened to apex, then pointed, apex slender, hooked. Thorax with low double posterior tuft. Abdomen smooth, broad, conical, pointed. Tibiæ with appressed scales.

"A moderately large genus, ranging over the whole world, but principally characteristic of America. Imago flying at dusk, feeding on the wing."--(Meyrick.)

This genus is represented in New Zealand by one almost cosmopolitan species.

SPHINX CONVOLVULI, L.

(_Protoparce distans_, Butl. _Sphinx convolvuli_, Meyr., Trans. N. Z. Inst. xxii. 213.)

(Plate XIII., fig. 1.; Plate III., figs. 13 and 14 varieties of larvæ.)

This handsome insect often occurs in the northern portions of the North Island, but becomes very rare southward of Napier and New Plymouth. In the South Island it has been taken at Nelson, and recently a very mutilated specimen of what appears to be this species has been found by Mr. Philpott, near West Plains, Invercargill. With these exceptions I have not heard of its appearance in any other localities in the South Island.

The expansion of the wings is about 3½ inches. The fore-wings are greyish-brown with several irregular, darker markings near the base; and a broad, dark, central band; beyond the central band there is a very irregular, pale grey, toothed line. The hind-wings are yellowish-grey, with four transverse, darker stripes, the outermost one strongly toothed. The head and thorax are dark grey, paler on the back, with two conspicuous tufts of pale grey hair on the shoulders. _The abdomen is grey, striped on the sides with rose-colour and black._

The larva feeds on _Convolvulus_. Like many of the caterpillars of the _Sphingidæ_, there are two very distinct varieties: one is bright green, with white spiracles, and a series of diagonal yellow lines above them; the other is dull yellowish-brown, with broad blackish-brown dorsal and ventral lines, and a series of triangular blackish spots above the spiracles, which in this variety are jet-black. In both these forms of {100}larvæ the anal horn is dark red tipped with black, and the skin is covered with numerous fine wrinkles. The length of the caterpillar when full grown is 3½ inches.

About the middle or end of February these larvæ generally bury themselves in the ground, where they are transformed into pupæ. They remain in that condition until the following summer.

The pupa is about 2 inches in length and is of a dark mahogany-brown colour. It is furnished with a large curved process, projecting from the lower side of the head, and containing the enormous proboscis of the future moth.

The perfect insect appears in November and December. It flies with incredible velocity at evening dusk, and is often observed hovering over flowers, and whilst poised in the air above them, extracts the honey with its long proboscis. Mr. A. P. Buller has very kindly furnished me with the following interesting notes on the habits of this species, as observed by him in the Auckland district:--

"During the summer of 1879 I came across _S. convolvuli_ in great numbers, near Ohinemutu, in the Hot Lake district, frequenting at dusk a tall, delicately perfumed meadow flower (_Oenothera biennis_, commonly called the evening primrose). They were to be seen on the wing soon after sundown, and on warm, still evenings literally swarmed. It was an extremely pretty sight to watch their rapid movements as they darted from flower to flower, never alighting, and keeping up a constant vibration of their wings as they probed the yellow blossoms. They appeared to be extremely local, for I only met with them on a few of the grassy slopes round the shores of Lake Rotorua. I visited the same locality two years later, at the same season, and only occasionally saw one, although the evening primrose was in full bloom at the time. In 1882 I captured several at flowers of the trumpet-tree (_Brugmansia_) in a garden near Auckland. The same summer I found large numbers of the larvæ at Waiwera (near Auckland), on a species of convolvulus growing in profusion on the sandhills in the vicinity. Although the larvæ were so abundant I never came across the perfect insect. I obtained some twenty or thirty of the pupæ, but unfortunately was never successful in hatching out the imago. As far as my knowledge goes, this beautiful moth is confined to the Auckland and Waikato districts, although I have heard of a single specimen being taken in Hawkes Bay."

I am also much indebted to Mr. Buller for the loan of a very perfect specimen of this moth, expressly lent to me for figuring and describing in the present work.

Mr. Meyrick informs us that this insect occurs throughout Europe, Asia, Africa, Australia and the islands of the South Pacific, wherever a suitable situation is found, and has been met with far out at sea.[43] In America it is represented by a form which seems to be regarded as specifically distinct, but which he thinks is probably identical. If this be the case the insect is practically cosmopolitan.

{101}III.--THE LASIOCAMPINA.

Not represented in New Zealand.

IV.--THE PAPILIONINA.

The _Papilionina_ are distinguished by the following characters:--

"Head rough-haired. Ocelli absent. Tongue developed. Antennæ slender, dilated apically, forming a gradual or abrupt club. Labial palpi moderately long, more or less rough-haired, terminal joint rather pointed. Maxillary palpi obsolete. Thorax more or less hairy. Fore-wings with 1_b_ simple, 1_c_ absent, 5 usually from or above middle of transverse vein. Hind-wings without frenulum, 1_c_ absent, 3 and 4 usually connate, 8 rising out of cell near base, rapidly diverging."--(Meyrick.) (See Plate I., figs. 7, 8, 15, 16, 25, 26, 27.)

This is one of the most interesting groups of the Lepidoptera. The insects comprised in it are popularly known as butterflies, and from their bright colouring and conspicuous appearance are always favourites with beginners. The _Papilionina_ attain great development in the tropics, especially in South America, where, it is said, a single valley sometimes contains as many species as the whole of Europe. In New Zealand there are only fifteen species of butterflies, the group being extremely poorly represented both here and in the South Pacific Islands.

Formerly the _Papilionina_ was known as the _Rhopalocera_, and was regarded as constituting a division of equivalent value to the remainder of the Lepidoptera, which was termed the _Heterocera_. For some time past entomologists have, however, practically abandoned this classification of the order, the _Heterocera_, or moths, being clearly composed of several groups each of equivalent value to the _Rhopalocera_, or butterflies. Mr. Meyrick states in his 'Handbook of British Lepidoptera' that the _Papilionina_ "stands rather conspicuously isolated at the present day, but there is little doubt that its origin must be traced to the _Thyrididæ_, a family of the _Pyralidina_."

In this group the wings are generally held erect in repose, the under surface of the hind-wings and the apical portion of the under surface of the fore-wings being nearly always protectively coloured, these being portions of the wings exposed to view when the insect is at rest. There is an unusual amount of ornamental colouring on the upper surface. The flight is invariably diurnal. The larva has ten prolegs.

The three following families of _Papilionina_ are represented in New Zealand:--

1. NYMPHALIDÆ. 2. SATYRIDÆ. 3. LYCÆNIDÆ.

{102}Family 1.--NYMPHALIDÆ.

"Anterior legs in both sexes much reduced, useless for walking; posterior tibiæ without middle spurs. Fore-wings with veins 8 and 9 out of 7. Hind-wings with præcostal spur." (Plate I., figs. 7 and 8.)

"An extremely large family, mainly tropical. The species are of large or moderate size, usually dark-coloured, with light or bright bands or rows of spots.

"Ovum cylindrical or sub-conical, ribbed and often reticulated. Larva with pairs of tentacles or more usually series of bristly spines. Pupa exposed, suspended by the tail, often angular or with metallic spots."--(Meyrick.) (See Plate III., figs. 1, 2, and 3 larvæ, 27, 31 and 32 pupæ.)

We have three genera represented in New Zealand:--

1. ANOSIA. 2. VANESSA. 3. JUNONIA.

Genus 1.--ANOSIA.

"Eyes glabrous. Club of antennæ elongate, gradual. Fore-wings with vein 10 separate. Hind-wings with transverse vein present." (Plate I., figs. 7 and 8, neuration of _A. erippus_.)

"A genus of moderate extent, generally distributed within the tropics, with two or three species ranging beyond them. Imago with termen of fore-wings sub-concave. Larva with pairs of long tentacles. Both larva and imago are protected by a strong nauseous scent, or taste, and are uneatable to birds."--(Meyrick.)

We have two species in New Zealand.

ANOSIA ERIPPUS, Cr.

(_Papilio archippus_, Fabricius, Spec. Ins., p. 55, n. 243 (1781). _Danais archippus_, Butler, Butterflies of N. Z., Trans. N. Z. Inst. x. 265. _Anosia plexippus_, L.)

(Plate XI., fig. 1, fig. 2 under side; Plate III., fig. 3 larva, fig. 27 pupa.)

This handsome insect has occurred from time to time at various localities in both the North and the South Islands, but does not appear to be generally common. Particulars of the early captures of this butterfly are thus given by Mr. Enys[44]: "First recorded as a New Zealand insect by Mr. Fereday, in a paper read before the Canterbury Institute, January 2, 1874, and printed in vol. vi. of 'Transactions.' Mr. Fereday received the butterfly from F. H. Meinertzhagen, of Hawkes Bay. Dr. Hector also obtained it in Westland. It has also been caught near Auckland. In vol. xi. of 'Transactions' Mr. F. W. Sturm records that he first saw this insect, or a closely allied one, at the Reinga, up the Wairoa River, Hawkes Bay, December, 1840, or January, 1841. In 1848 he captured a number at the Waiau, a tributary to that river. Again in 1861 he captured three on the Rangitikei River near Mr. Birch's run. He also records other captures." From these records it will be seen that the insect was observed as early as 1840, and it thus seems scarcely probable that it was accidentally introduced by man, as Mr. Butler appears to suppose.[45] Recently _A. erippus_ has occurred many times in the neighbourhood of Cook's Straits. In 1879 several specimens were bred from larvæ found by Mr. C. W. Lee near Wangaehu. In 1881 I captured two specimens near Nelson and saw three others. In 1890 two specimens were taken by Mr. R. I. Kingsley, and in January of the following year I captured two more, all near Nelson. During the autumn of 1892 {103}one specimen was taken near Otaki by Mr. Rutherfurd, and several others were seen. The same year a specimen was also taken by Sir James Hector at Petone. In 1896, I understand from Mr. Kingsley, several specimens were again seen in the Nelson district.

The expansion of the wings is from 3¾ to 4¼ inches. Above, all the wings are rich orange-brown bordered with black, the veins are also black. There are two rows of small white spots round the margins of all the wings, and several orange-brown spots near the apex of the fore-wings. Beneath, the markings are similar, except that the white spots are larger, and the hind-wings are very pale yellowish-brown. The male has a black chitinous spot on vein 2 of the hind-wings which is wanting in the female; the wing-veins in the male are also slightly narrower.

The larva of this insect feeds on most of the different kinds of milkweed (_Asclepias_), and also upon dogbane (_Apocynum_). A single caterpillar, fully grown, which was found in a building in the centre of the town of Wellington, formed the subject from which the figures of the metamorphosis of this insect were taken, but this specimen did not afford sufficient material for an exhaustive investigation of the life-history. The following account, taken from Professor Riley's 'Third Annual Report of the Noxious, Beneficial, and other Insects of the State of Missouri,' is therefore inserted:--

"The egg is invariably deposited on the under side of a leaf, and is conical and delicately reticulate with longitudinal ribs, and fine transverse striæ. It is yellowish when first deposited, but becomes grey as the embryo within develops.

"In about five days after laying the egg hatches, and the young larva as soon as hatched usually turns round and devours its egg-shell--a custom very prevalent with young caterpillars. At this stage it differs considerably from the mature larva; it is perfectly cylindrical, about 0·12 inch long, and of much the same thickness throughout. The head is jet black and polished; the colour of the body is pale greenish-white, with the anterior and posterior horns showing as mere black conical joints, and with two transverse-oval black warts, nearer together, on the first joint. It is covered with minute black bristles, arising from still more minute warts.