Part 63

This beautiful insect occurs occasionally in forests in both the North and the South Islands. It has been taken at Wellington, Nelson, Castle Hill, Akaroa, Mount Hutt, West Plains and Otara.

The expansion of the wings is 1¼ inches. The fore-wings of the male are pale orange-brown, with a doubly toothed black transverse line near the base, and a less acutely toothed line beyond the middle; between these there is a black mark on the costa; the termen has two large projections, and several smaller ones; between the outer transverse line and the termen there are several small black markings. The hind-wings are yellowish, clouded with orange-brown towards the termen, which also has several projections; there is a faint blackish line near the base, and a much stronger black line near the middle, starting from the dorsum and reaching about half-way across the wing. The female has the fore-wings dark brown, with the central area between the two transverse lines paler; the hind-wings are also considerably darker than those in the male.

This species varies a little in the depth of the ground colour, but not otherwise.

The perfect insect appears in December, January and February. It frequents dense forest, and is generally disturbed from amongst ferns and undergrowth.

{94}Genus 8.--IPANA, Walk.

"Face roughly haired. Antennæ in male simple, shortly ciliated. Palpi as in Declana. Thorax densely hairy above and beneath, with slight median crest. Abdomen in male elongate. Femora densely hairy; posterior tibiæ in male short and much swollen, furnished on inner side with very large dense tuft of hairs. Fore-wings in male without fovea; veins 10 and 11 separate."--(Meyrick).

We have one species in New Zealand.

IPANA LEPTOMERA, Walk.

(Ipana leptomera, Walk., Noct. 1662.)

(Plate X., figs. 29, 31, and 31A varieties, 30 .)

This species is common in the neighbourhood of Wellington, and I expect generally distributed throughout New Zealand; but as there appears to have been some confusion in Mr. Meyrick's papers between it and the female of Declana junctilinea, I am unable to assign the localities there mentioned to either of the species.

The expansion of the wings of the male is 1½ inches, of the female 1-3/8 inches. The fore-wings of the male are uniform pale brownish-ochreous, generally with two transverse series of minute darker brown dots parallel to the termen, and two or three similar dots near the middle of the wing. There is a series of very small parallel brown lines on the costa. The hind-wings are greyish-brown with two very deep indentations in the termen. The female has the fore-wings pale grey, and the hind-wings darker grey; the markings and outline resemble the male.

In a few male specimens I have observed four large black spots on the fore-wings, two near the base, and two near the termen. All these spots are sometimes joined together by a very broad black band, which extends along the whole of the central portion of the fore-wings. I have also a male specimen in which the fore-wings are entirely marbled with dark grey. In the female two or three moderately large spots are occasionally present on the fore-wings, near the termen. All these varieties appear to be much scarcer than the typical form.

The larva, which feeds on manuka (Leptospermum), has ten legs. It is rather slender, dark brown, mottled with grey and dull red. There are two large tubercles on the sides of the seventh and eighth segments. It is a sluggish caterpillar and is generally seen in a motionless condition, clasping the stem of its food-plant with its prolegs, and holding the rest of its body in a perfectly rigid position like a small branch. The pupa is enclosed in a cocoon of silk and refuse on the surface of the ground.

The perfect insect appears in January, February and March. It is a forest-dwelling species, and may often be captured in some numbers, at dusk, on the flowers of the white rata (M. scandens). It is very sluggish and nearly always drops to the ground when disturbed and feigns death.

Genus 9.--DECLANA, Walk.

"Face roughly haired. Antennæ in male bi-pectinated to apex or simple. Palpi with second joint ascending, rough-haired, terminal joint rather long, slender, clavate, porrected. Thorax densely hairy above and beneath, with more or less developed median crest. Femora densely hairy. Fore-wings in male without fovea; vein 6 sometimes out of 9, 10 sometimes out of 9, connected or anastomosing with 9, 11 sometimes out of 10, sometimes connected or anastomosing with 10."--(Meyrick.) (Plate II., figs. 56 and 57, neuration of Declana floccosa, 58 head of ditto.)

We have seven species.

{95}DECLANA ATRONIVEA, Walk.

(Detunda atronivea, Walk., Suppl. ii. 619. Chlenias (?) manxifera, Fereday, Trans. N. Z. Inst. xii. (1879), 268, pl. ix. 1. Detunda atronivea, Meyr., ib. xvi. 101.)

(Plate X., fig. 33 , 34 ; Plate III., fig. 18, larva.)

This very handsome and conspicuous insect appears to be restricted to the North Island, where it is rather rare. It has occurred at Wellington, Otaki, and Napier.

The expansion of the wings of the male is 1-5/8 inches, of the female nearly 2 inches. The fore-wings are brilliant shining white, with numerous black markings; these consist chiefly of three irregular branching transverse bands, and a series of wedge-shaped spots on the termen; the larger markings are brownish in the centre. The hind-wings are dark grey, becoming almost black on the termen, with a fine wavy transverse black line.

This species varies considerably in the size and shape of the black markings on the fore-wings, which are often slightly different on the opposite sides, in the same specimen.

The eggs of this moth are oval in shape, slightly roughened on the surface and light blue in colour. They are deposited towards the end of October. The young larva escapes by gnawing a hole out of the side.

When first hatched it is dull brownish-black, with creamy-white lateral lines and prolegs; the head is reddish. It feeds on Panax arborea. After the first moult the lateral lines become much wider, especially towards the head. After the second moult the two dorsal tubercles are fully developed, the thoracic segments much swollen and flattened above, the latter bearing traces of the black markings of the full-grown larva. After the third moult the larva becomes a dark brownish colour inclining to chocolate on the dorsal surface. The characteristic markings on the penultimate and anal segments of the adult larva now appear, and the dorsal tubercles are yellowish in colour; the extra prolegs are very small, and are visible as wart-like appendages on the lower surface of the tenth segment.

The full-grown caterpillar is a remarkable-looking animal. The head is very small; the first three segments of the body are enormously swollen and flattened above, the flattened portions being white, with several small black ring-shaped markings; there is a pair of large yellowish tubercles on the dorsal surface of the seventh segment, and two smaller ones on the tenth and eleventh segments; the larva is much stouter towards the posterior extremity, especially behind the ninth segment; the penultimate segment is furnished with a large creamy-white ridge, starting on the back and proceeding downwards and forwards; the extra pair of prolegs is small and only occasionally used in walking. The general colour of the larva is brownish- or blackish-green; the tenth and eleventh segments are generally darker, and there are many fine parallel lines of darker colouring on the central portions of the larva; the whole insect is also speckled with black; the spiracles are red. The larva varies a good deal in colour, but its peculiar structure will at once distinguish it from any other.

These larvæ often coil themselves up when at rest, clinging firmly with their large prolegs to their food-plant. Whilst thus engaged they have a very remarkable appearance. I have not yet ascertained the precise object of the peculiar shape and coloration of this caterpillar. It appears to resemble very closely a lichen-covered twig, but I suspect in this case there is something more special aimed at.