NATURE NOTES

New Zealand Herald, Volume LXX, Issue 21562, 5 August 1933, Page 1 (Supplement)

NATURE NOTES

INSECT'S STRANGE DEVICE

BY J. DHUSIMOND, I'.L.S., F.Z.S

Mr. 0. B. Walker's report that the fat and well-liking caterpillar of the hawk-moth uses a peculiar horn on its back as a weapon, recalls an original observation of the saino sort by Miss E. V. Elliott, of Motunau, North Canterbury. Her contribution to entomology deals, with the young stage, the grubhood of a beetle, not with a caterpillar. It is the eucalyptus tortoisebeetle, Paropsis dilatata, an Australian that has come to New Zealand with the useful and beautiful Australian eucalypts, on whoso leaves it feeds. As a perfect adult, it is only about onethird of an inch long, but it is a quarter of an inch deep, and is convex, reddish, yellowish, brownish or pinky. When it crawls along on its six slender feet, feebly waving its thread-liko feelers, it looks like" a very small tortoise. As a grub, before reaching maturity, it is yellow or pink. In that stage, as well as in the adult stage, it devqurs eucalyptus leaves, devoting its whole life to damaging the trees. Dr. D. Miller, of the Cawthron Institute, has noted at the tip of its body a false foot like a sucker. This helps its true feet, by which it crawls with a looping gait.

Miss Elliott discovered that, although this little grub seems utterly defenceless, it has a devico to use against enemies. If it is picked up by a bird, or is disturbed in any other way, it produces a pair of horns from its back and squirts out of them a spray of fluid that smells strongly of eucalyptus. This is distasteful to birds, wasps, ichneumon flies and other enemies. It may bo presumed that the grub frightens most of its enemies away, and is left in peace to stuff itself full of material from the leaves, and at the close of its grub stage to descend to tho ground, there to pass a time as a hairy chrysalis, emerging from inertia in a few days a spick-ipd-span tortoisebeetle, eager to ascend the nearest eucalypt.

The discharge of fluid when alarmed is not common among insects, but it has been observed in different orders. %lany grubs of sawflies, which, as hymenoptera, can claim relationship with ants, wasps and bees, eject a disagreeable fluid from the mouth or from pores in tho skin, sometimes sending out a spray a little distance from the body. There seems little doubt that this protects the grubs from the attacks of parasitic insects intent on laying eggs in the grubs' soft bodies. The bombardier beetle of the Old Country defends itself by discharging a fluid explosively. New Zealand has no bombardier beetles. Australia has several species of them, including one which lives under stones. On being disturbed, it expresses its resentment by-discharg-ing a cloud of vapour, with a distinct report.

Members of another family of beetles, the Paussidae, unrepresented in New Zealand, but with about sixty species in Australia, related to the carabs, are able to bombard. These remarkable beetles sometimes have grotesque feelers, luminous at night. Major R. W. G. Hingston regards luminosity as more important to beetles than power to bombard or to spray with unpleasant fluid. Displays of light by luminous beetles have been explained as love-sig-nals between the sexes, as warnings to other nocturnal creatures that the lamp-bearers are distasteful, even nauseous, and should be left alone, or as mere pastimes devoid of utilitarian purpose. Major Hingston says he is convinced that they are intended to affright enemies and are as effective as discharges of fluid. Ready to fight, a luminous beetle throws out its threatening flame. In piping times of peace, it puts out its light and enjoys the advantage given by its concealing dress. The sudden glow is like the flash of a naked sword in a man's hand.

To support his theory, Major Hingston mentions the case of a luminous beetle that flew under a verandah in Singapore at night. A lizard advanced to seize it. The beetle flashed and the lizard turned and fled. Twelve dead luminous beetles were placed in a box. Six of them which had been dead for a fairly long time did not glow.The others killed recently, sent forth bright lights. Tbe following morning it was found that ants had eaten the six without lights, but had not touched the six with lights. Major Hingston says he cannot see in luminosity in the animal kingdom, anything except expression of alarm or anger. He applies this theory to tho full splendour of light displayed by some fishes that live in the black darkness of the ocean's depths. He sees in them battle flames of the ocean bed.

Monday next will be an important ornithological anniversary in New Zealand. On August 7, thirty-five years ago, a Notornis was caught in the Middle Fiord of Lake Te Anau, and the fourth specimen o'f a rare species of bird, a large, heavy, massive and flightless rail, which has not been authentically reported since, was added to the world's collection. The discovery of a fifth specimen is possible. In the' meantime, the fourth specimen in Otago Museum is the best, surpassing in quality, the first and second specimens in the British Museum, and the third, which the Dresden Museum bought in London for £llO. August 7, 1898, was a Sunday. In the morning, Mr. Donald Ross and his brother, Mr. John Ross, who were interested in a passenger steamer enterprise on Lake Te Anau, lay in their tent in a small bay in the Middle Fiord, near the mouth of Snag Burn and opposite tlie Bute Islands. They knew the notes of most of the native birds. About eight o'clock they were surprised to hear a note they had not heard before. Tired after a week's hard work, they did not get up to look for the stranger, but they discussed it and agreed that it might bo a Notornis.

In the evening, soon before dark, Mr. Donald Ross went for a walk along the shore with his brother's dog, Rough. As thflro were kakapos, wekas and a few kiwis in the bush, Rough was held in. When tliey were about 150 yards back of the camp, Rough made a determined dive. Rushing forward for about thirty feet, it caught a bird under the overhanging branches of a beech tree. Dusk had fallen too heavily for Mr. Ross to distinguish the bird: He thought that it was a weka. Rough obeyed a call to bring in tho captive. Mr. Ross then saw that another Notornis had been found. It was alive, but half an hour later its head suddenly drooped to one side. So died the fourth Notornis. The Government ottered £250 for tho specimen. In accepting the offer, tho brothers made a condition that it should bo placed in Otago Museum. Rough, who discovered and caught the Notornis and caused its death, died in lnvercargill years ago. Mr. Donald Ross is fossicking among tho alluvial gold deposits of Coal Creek Flat, near Roxburgh, Central O'tago. Mr. John Ross is farming at Quarry Hills. Tokanui, Southland. It is eighty-four years since a party of sealers in Duck Cove, Resolution Island, roasted and ate the first. Notornis, but refrained from eating the skin and the feathers; about the same time since Maoris caught the second Notornis on Secretary Island, Resolution Inlet; and fifty-four years since rabbiters caught the third on the le Anau Downs, between the Mararoa and Upokororo Rivers. i