NATURE NOTES.

New Zealand Herald, Volume LXVI, Issue 20420, 23 November 1929, Page 1 (Supplement)

NATURE NOTES.

By J. DRUMiIOND, F.L.S., T.Z.S.

A TUSSOCK BUTTERFLY.

Several interesting features aro possessed by a butterfly sent by a Tai Tapu, North Canterbury, correspondent. It belongs to a species with a strange and puzzling distribution. Most members of the species favour lowland tussock land' 3 from Christchurch to Invercargill. Others seem to live in only -the mountains of Nelson and Marlborough, at altitudes from 2000 ft. to 4000 ft. It has not been reported from the North Island, nor havo any of its allies been recorded there, but two closely allied species occur in tho mountains of Chili. Another feature is the remarkable variation in marks and colours on the wings. These, apparently, arc influenced by local conditions. The wings of tho Tai Tapu specimen are brownish-grey near the body, then fawn colour half-way toward the tips, margined at the tips again with brownish-grey. In each fawn-colour area on the fore-wings there is a round patch of black. In each patch there are two white dots. Each hind-wing has three smaller black patches and each patch has one white dot.

Even an experienced butterfly-man hardly recognises this form as a member of the same species as the typical form, with dark, dull brown wings and bright orange-brown areas instead of fawn colour. Yet between these extreme forms there is a host of intermediate forms, linking up the extremes and labelling all with one name, Argyrophenga antipodum. They belong to the group of the Satyrids, associated for some reason with the mythical satyrs, and very widely distributed over the world. There are almost 1000 species iu the group. About one-third of the butterflies of Europe are members of tho group. In England they include the ringlets, tho marble whites, tho meadowbrowns and tho greylings.

[ The Tai Tapu correspondent refers to this butterfly's incorispicuousness: " When an attempt is made to catch it," he states, " it drops down on to grass or straw with closed wings and shams death, and then there is difficulty in finding it." Resting on the blade of a tussock, it takes advantage in the same way of its protective colours. Mr. G. V. Hudson, of Karori, Wellington, has watched members of the species fly amongst tussock grass in a feeble and aimless way, but, when danger threatens, plunge into a tussock and close their wings, becoming quite invisible. On the Tai Tapu specimen there are silver streaks between the veins on the under side of the hind-wings. Exposed at rest, on tussock or straw, these are an admirable example of the principle of protective colouration, more marked in moths and butterflies, perhaps, than in any other order in the animal kingdom.

While rearing these butterflies Mr. Hudson watched their transformations through the stages of their marvellous life history, looking on at one of the wonders of the universe. Out of an egg there comes a caterpillar about three-sixteenths of an inch long. Its pale pinkish strawcoloured body is another example of protective colouration. Fully grown to an inch long, the caterpillar wears a green garment, striped with yellow. Its body is attenuated and tapering. Very fine green hairs all over the body give it a velvety appearance. Or it may pub on a pale brown costume, with fine darker brown and reddish-lines. >

As a chrysalis it wears brighter green or homely pale brown. Suspended by its tail, head downwards, to an upright blade, well hidden among the tussock, it goes through a stage of inertia until it feels the mysterious inner impulse that brings it forth in its glory as a perfect butterfly, one of the most beautiful creatures in all creation. As a chrysalis it has neither legs nor arms. Mr. Hudson expected that, in extricating itself from tho skin developed in the caterpillar stage, it would fall. Instead, it accomplishes this task with absolute surety. Supple and contracting joints of the abdomen, Mr. Hudson states, arc used in place of legs. The shrunken caterpillar skin irf suddenly grasped between tho folds of tho joints, used like a pair of pincers. The tip of tho body is disentangled. The chrysalis stays pendant for a few seconds, and then, by violent jerks aud whirls, the old skin is dislodged.

Not at present, probably, but next month, and until March, people who go up into the mountains of the South Island may see another satyrid, as black as night. This is an alpine butterfly, Erebia plulo, seen more frequently on mountain ranges than on isolated peaks, flying; lazily in scorching sunlight, as described by Mr. Hudson, but quickly retreating into crevices between stones when the sun is obscured. In spito of its fondness for its alpine home — : it has been seen 6000 ft. above sea-level—it loves the sunshino as deeply as tho scarlet pimpernel, which languidly closes its flowers when the sun ceases to shine. Tho black butterfly—a very rich bronzy black, cm-

bellishe'd with several tiny white spots—seldom settles on grass, preferring to settle on shingle, which, Mr. Hudson points out, owing to tho rarefied air in high altitudes, soon becomes greatly heated by tho sun's ravs.

Much rarer than the black butterfly is its smoky-brown cousin, Erebia Butleri, still another New Zealand Satyrid. Unlike the black butterfly, it seldom settles on the shingle, of tho South Island mountains where it lives. When it needs a rest from its feeble flights it usually selects mountain grasses. As soon as

the sun is obscured it retreats into tufts of grass, where it hides closely until the sun comes out again. Tho first specimen of this Satyrid was discovered fifty years ago by Mr. J. 1). Enys, a naturalist of tho early days, in the historical Whitcombe's Pass, leading over tho Southern Alps. It has been taken 011 tho Humboldt Range, which lies at tho head of Lake Whakatipu, and on Mount Earnslaw and Mount Cook, but nofc in the North Island.

In the North Island and the South Island thcro is a Nymphalid butterfly rarer, in New Zealand, than any of the Satyrrds, but a member of the same family. Its name is Hypolimnas bolina. It has rich brownish-black wings, each wing with a white blotch surrounded by brilliant Hashing blue. It beautifies landscapes in Java. New Guinea, tho Loyalty

Islands, Fiji, Polynesia, and thtj regions of the Orient, and is very plentiful in Australia, but it occurs so irregularly in New Zealand that Mr. Hudson believes that it is only an occasional immigrant, which has not established itself permanently. The honour of discovering 'this comparatively largo and very brilliant butterfly in New Zealand belongs to Dr. Andrew Sinclair. His name has an

honourable place in the list of Now Zealand naturalists. He was a surgeon in the Royal Navy, and mainly a botanist, who wished to give up his lifo to studying plants. It is eighty-eight years since ho first stepped ashore at the Bay of Islands and revelled in the plant life there. Returning to Australia, he met Captain 11. Fitzroy, New Zealand's second Governor, who engaged him as private secretary. Soon after, he was appointed Colonial Secretary. Almost all his leisure time was given up to botany. Freed from official duties, ho joined Sir .Julius Haast in a notable geological and botanical expedition into tho Southern Alps. He imprudently tried to ford the Rangitata River, South Canterbury, when it was dangerous, and was drOWDGu. _ JllS lonely grave lies on tho bank of tbo river.,