NATURE NOTES.

New Zealand Herald, Volume LXVII, Issue 20716, 8 November 1930, Page 1 (Supplement)

NATURE NOTES.

BY J. DIIUMUOND F.L.8., F.Z.S.

AN EARTH-MEASURER.

Members of the most attractive group of the larger moths arid butterflies in New Zealand are called geometers, earthmeasurers, becauso their caterpillars are compelled, when walking, to arch the middle of the body. The arch rises and falls as the caterpillars walk along with a looping gait. This gives an impression that they are carefully measuring their route, more often on a plant than on the earth. In America they are called measur-ing-worms, in the Old Country loopers. They are moths, not butterflies. Their colours as perfect moths, flitting in the air, often are protective, resembling their surroundings, some of them mimicking moss-covered tree-trunks and beautiful lichens. New Zealand is known to have about two hundred and forty five species of them, a large number in a somewhat poverty-stricken moth and butterfly life of only about twelve hundred species. The Old Country has two hundred and seventy-seven earthmeasurers, and the whole of Europe seven hundred and seventy.

As a group, New Zealand's earthmeasurers, referring again to the perfect insects, not the caterpillars, are much handsomer and gayer than the Old Country's. Many of the New Zealanders are mountaineers. It is believed that novelties among them are waiting to be discovered in the wild country in the south-west of the South Island, a fact that should give an additional interest to holiday and exploring parties in that wonderful district. The latest report of an earth-measurer is from Mr. O. Pocock, of Mill Creek, Whitianga, Mercury Bay. He wrote on September 14—" This evening my wife and I were startled by tho beauty of a moth that fluttered round tho lamp. 1 I hope that from a rough and unworkmanlike sketch you will be able to identify it, and to tell us about it. Its forewings were silvery white, veiy sharply marked lay broad, wavering lines rf black. Its eyes were large, and shone ruby-red in the light." It is a form of a species that' may for convenience be called the silverwhite by people who do not like its pretentious. official name in the moths' and butterflies' " Who's Who—Declana atronevia. New Zealand has nine or ten Declanas, almost all wearing neat, not gaudy, costumes, some delicate in appearance, some dull in greys and browns and some very rare. Mr. Pocock's species is somewhat' rare. It. seems to favour the North Island only. Tho slopes of Mount Egmont are-its favourite resorts.

It could hardly be expefcted that such a notable moth should escape the attention of Mr. G. V. Hudson, who knows more about New Zealand's moths and butterflies than anybody else does, and who traced the life history of this species from the egg to the perfect insect. Each oval egg, he states, is one thirty-second of an inch long. In colour it is a lovely light blue, like a tiny, exquisite jewel. Escaping out of its azure prison by gnawing a hole in the side, the caterpillar comes out into the world wearing a homely brownish-black costume and a red cap. Fully grown as a caterpillar, after changing its coat three times, it puts on brownish-green speckled with black and spotted with red. It often coils itself up when at rest, still clinging to its foodplant, which often is the five-finger tree.

When the mysterious impulse to advance from caterpillar to chrysalis is felt, it descends to the surface of the ground, nestles among dead leaves and other material, spins a light cocoon, and there, inert and dead to the world, slowly undergoes changes that produce a perfect moth with wings, antennae, and all. A flowerlover, it often may be seen in the evening flitting about blossoms, but lights lure it. Although nocturnal, it is seen occasionally in the daytime resting on tree trunks. Mr. Hudson is a strong supporter of the theory that, in many cases, the colours of insects, harmonising with their surroundings, hide their identity and protect them from enemies. He is convinced that the contrasting colours on this moth's wings harmonise so well that the moth does not attract the eye as a distinct object apart from the general landscape.

The most strangely marked Declana was first discovered on ' the Mount Arthur Tableland, Uelson, and later in Arthur's Pass and on mountains in Otago. Its forewings are a dark, rich, purply brown, each wing conspicuously marked by a very irregular while mark. Its hind-wings are bright orange. There is tawny hair on its head. So plentiful is it in Arthur's Pass that, at this season, individuals sometimes may be caught as they dash across the old road along which Cobb's coaches once rattled-. These moths fly very swiftly in the bright sunshine, but late in the afternoon is the best time to see them. They so love the mountains that they do not come down ou to the lowlands, preferring open mountainous country from two thousand feet to four thousand feet above sea-level. The females are duller, less active, and much rarer than the males. This species is Declana glacialis, the Declana of the glaciers. Another South Islander, Declana egregia. with creamy whiter wings, marked with dark brown and chocolate, is a lodger in the forests between Nelson and Stewart Island., It is not plentiful anywhere, but likes the colder parts, and has been reported most frequently from Stewart Island and the Southern Sounds.

Riding over the Puketi Plains, Bay of Islands, on fine days some years ago, Mr. J. Ogle, of Rangiahua, was entranced by skylarks singing overhead for miles, some soaring, some apparently high up out of sight, some darting back to earth. But, travelling over the same plains now: " You may hear a skylark trying to sing the song skylarks used to sing, but it is almost sure to, be sitting on a post. It docs not soar straight up, but rises on a lazy angle to a height of thirty or forty feet, utters a few half-hearted notes, does not dart down again as a true skylark should, but seems to steady itself for a few seconds, and finally decides to descend as lazily as it went up." For these reasons Mr. Ogle is disgusted witth skylarks these days.

In a letter written to maintain that the South Island as a songster, is equal to the North Island wood-robin, Mr. T. McGill, Rakaia, goes back fiftytwo years, when a cousin and he made their first long train journey into Southland, and stayed with relatives who lived between Mataura and Wyndham. Following is Mr. McGill's interesting account of his experiences.—" Their clay whare was close to the main bush, and our first night's experience was a true one of country life, as bush-rats swarmed over our bunks in the early hours of the morning. Where they left off, swarms of bush-fleas carried on tho good work, so that we were glad to rise early. The whole bush was alive with nativo birds. The outstanding songsters were the South Island wood-robins, which were very numerous. The whole bush was full of their melody. Now a flock of red-fronted p.irrakeets would swiftly wing their way across the tall rimus and matai trees. Then we would watch the yellow-fronted parrakeets, sometimes in pairs, as they settled in a broad-leaf tree. Again, we could hear the swish of the wings of the native pigeon, kereru, on their flights to a small forest of miro trees, to gorge themselves with the miro berries."