BEAUTY IN INSECTS

Auckland Star, Volume LXIX, Issue 220, 17 September 1938, Page 6 (Supplement)

BEAUTY IN INSECTS

By--A. W. B. Powell

EVERYONE ia interested in colour. Everyone therefore will be interested in the display of Oriental insects recently placed oa exhibition in the Auckland War Memorial Museum.

There was a time when nonatural history exhibition could be arranged other than in "cut and dried" systematic order— the specialist knows his classification by heart—detailed presentation" of this classification to the uninitiated often results in mental chaos, so that the visitor leaves with a bewildered rather than an enlightened mind. With its keynotes of colour and f6rm, all will find interest in this new exhibition, which is the work of the museum'a honorary entomologist, Mr. W. H. Hemingway, and his able assistant, Miss M. Carter, who haa attended to the artistic and highlv-skilled work of setting and mounting the specimens.

All the specimens* displayed were secured last year by Mr. Hemingway during a seven month*' visit to the East. Over 2000 specimen* were secured, mainly from" the Philippines, China, Japan, French Indo-Ghina, the Malay States, Sumatra and Java.

The following notes and impressions will enable those unable actually to see this mn*t attractive exhibition to lenrn something of the interest and splendour of tropical butterflies and insects. We in New Zealand are unfortunate in that our insert fauna is sadly lacking in large and brightly-colfmred species. For a country of it« size and climate, New Zealand is noted for its paucity of butterflies. lfl kinds only being on record, and only half of thie number are at all common.

Of course the entomologist in the field uses a net, but more often he secures hi* specimens by trick and trap. For instance, some of the largest and most colourful butterflies fly too higtt to b# netted, and even then are apt to be damaged. It happens that certain of these butterflies have disgusting testes, and many hare been secured by the collector setting in places frequented by

the insects such horrible things as bad meat, decaying fish and such like matter. The butterflies settle on such lures, and after gorging themselves are easily secured. Many moths may be secured by placing a mixture of stale beer, rum and molasses on tree trunks. Certain s|>ecies of beetles are caught in the same way. Needless to say, great patience is necessary to be exercised by the entomologist. This is so not merely when waiting fot certain insects to appear, but also when watching the habits of creatures. Much may be learned about the habits of anta and wasps "by sitting quietly down and watching sometimes for several hours at % time. The entomologist must also know something about the vegetation growing in hie collecting grounds. Sometimes the collector will know without seeing them that certain insects are to be found in and around a certain place from trees and shrubs he sees growing there. The sight of ccrtain insects will also be a certain indication that certain vegetation is to be found in the neighbourhood.

Not only is the collection noted for the galaxy of colour and form, bnt some of the world'* largest known insect# are re presented. Moths with a wing span of 10 inches, butterflies almost a* large, •nd beetle* over six inches in length, fearsomely armed with great claws and spiny processes, are among the eights. The world'* largest moth, coscinocera hercnles, an excellent specimen of which is shown, cornea from Queensland. The area of the wings 4* approximately 70 square inches. The prevailing colour is of warm brown, but its most remarkable feature a transparent window-like space ia tb« middle of each wing. The giant hercnles belongs to the silkworm moth family; its cocoon is lined with finest silk, the length of thread in each cocoon pTobably exceeding a mile. Unfortunately the silk spun by the hercules caterpillar la too flue for commer-

cinl purposes, otherwise a valuable industry mijrlit be added to those of Queensland, already so nicely endowed with natural resources.

Among the world's largest and most striking butterflies are the several species of '"bird-wing" butterflies, the ornitlioptera. They are noted for the •rrcat differences in coloration between the sexes. Perhaps the most remarkable known instance is in the New Guinea paradisea, the female of which is a large, sombre creature of black, white and grey, but the male is brilliantly coloured with gold and green, and is made additionally remarkable bv a lonjr tail of unusual lorm on each hind win;.'.

Just why many creatures display brilliant coloratioa that makes them

conspicuous in tlie extreme has intrigued naturalists through the ages. Where the creature is coloured to harmonise exactly with its surroundings the protective factor is obvious—'the green preying mantis is almost invisible on green herbage, and a brown variety is equally well concealed on withered leaves. The value of colour is increased when tho markings also simulate the surface upon which an insect normally rests.. 1 have in mind a beautiful little local moth which has a win<r pattern of tine, close, horizontal, brownish lines on a buff ground. The sense of this pattern is at once apparent when the ninth is found in its natural resting place—on the undersides of dead leaves of the cabbage tree.

It was the groat Alfred linsscl Wallace who saw reason ill the gaudy display of certain tropic insects, which he interpreted as warning coloration. .Bird*

that prey largely upon insects know by experience that certain kinds are distasteful to them. What is more natural, then, than for such insects to advertise, making it quite clear to their likely enemies that conspicuous coloration may denote a distasteful or even poisonous composition. The Monarch butterfly, which has recently become common in Xew Zealand, is a case in point, both caterpillar and butterfly being of brilliant colour, as well as of unpalatable composition. There is the extraordinary case of an American butterfly which is almost indistinguishable from tho Monarch, yet it is not closely related, yet is sweet to the taste. By imitating the Monarch this butterfly shares the respect shown to the Monarch l>v its enemies.

In the exhibition is a case featuring a collection of inject* from the junglecovered. ruins of the ancient city of Angkor, in French Indo-Chin«. "It is indeed a small world, "for there is our old friend the Monarch, also the Blue Moon, an occasional migrant to this country."

Last summer tie Monarch showed that it had definitely established itself in Auckland. It had been known in New Zealand for many years, but has never before been known commonly. Its sudden spread was due, in part, to human cultivation of its food, the "swan plant," a species of milk weed which has recently found favour with suburban gardeners, also to the activities of Mr. Skeates, of Titirangi, who has been breeding and liberating Monarche for several years.

The Monarch caterpillars attacked the swan plants so vigorously last season that many of the plants have not recovered. In my own garden one plant, seven feet in height, was so badly attacked that it died. However, in my opinion, the sight of an occasional Monarch on the wing enlivens the landscape far more than does the sombre, straggly swan plant. I would advocate increased planting of this, the Monarch's, food plant, for no other reason than to foster this handsome, harmless insect.

While in Sydney recently I visited the home of a butterfly specialist, Dr. G. A. Waterhouse. and found his delightful home at Killara carefully planted with the food plants of as many different kinds of butterflies as possible. In this way he attracted to his own home many Species that could be thus studied at his very door.