CHAPTER VII
"THE LORD AND MASTER OF FLIES"
Among the curious creatures native to the island is a fierce cannibalistic fly. Fully an inch in length and bulky in proportion, it somewhat resembles a house-fly on a gigantic scale, but is lustrous grey in colour, with blond eyes, fawn legs, and transparent, iridescent wings, with a brassy glint in them. The broad, comparatively short wings carry a body possessing a muscular system of the highest development, for the note flight produces indicates the extraordinary rapidity of the wing vibrations. Some swift-flying insects are said to make about eight hundred down strokes of the wing per second. This big fair fellow's machinery may not be equipped for such marvellous momentum, but the high key that he sounds under certain circumstances indicates rare force and speed. No library of reference is available. The specific scientific title of the insect cannot therefore be supplied. Possibly it does not yet possess one, but it is a true fly of the family ASILIDAE, and being a veritable monster to merely sportful and persistent if annoying flies of lesser growth, no doubt it will continue to perform its part even though without a formal distinction. Its presence is announced by an ominous, booming hum. It passes on one side with a flight so rapid as to render it almost invisible. You hear a boom which has something of a whistle, and see a yellowish glint; the rest is space and silence. In half a minute the creature returns; and thus he scoops about, booming and making innocent lightnings in the clear air. The tone is demonstrative, aggressive, triumphant; but the monster is only reconnoitring—seeing whether you have any flies about you. You may have boasted to yourself—there being no friends about to tolerate your egotistical confidences that there are no flies about you; but the big, booming creature has his suspicions. Apparently in his opinion you are just the sort of country to attract and encourage flies, and he does not immediately satisfy himself to the contrary. But should you witlessly happen to have attracted the companionship of ever so innocent a fly, the awful presence seizes it on the wing and is away with the twang of a bullet. It will pick a fly from your sunburnt arm—no occasion for coats here—with neatness and despatch and leave wondering comprehension far behind. And having seized its prey, it may, haply, seek as it booms along the nearest support on which to enjoy its meal. Then you see what a terrific creature it is. One favoured me with a minute's close observation. By a hook on one of the anterior legs (it possesses the regulation half-dozen) it had attached itself to a tiny splinter on the under-side of the verandah rail, and so hung, the body being at right angles to its support. Thus stretched, the leg appeared fully two inches long, and with the rest of its legs it clasped to its bosom the unfortunate little fly, shrunken with distress, the very embodiment of hopeless dismay. No sight which comes to memory's call equals for utter despair that of the little insect, which no doubt in its day had provoked a big lump of irritation and strong but ineffective language. Hugged by its great enemy, it seemed aware of its fate, yet unreconciled to it. Pendant by the one long, slender leg, as if hung by a thread, the blond monster seemed quite at ease over its repast. That was its customary pose and attitude at meal-times. As far as observation permitted, it was pumping out the blood of its prey, but before the operation was finished it forbade closer scrutiny by humming away with a note of savage resentment—a rumble, a grumble and a growl, ending in a swelling shriek.
It would be interesting to know how many flies of the common vexing kind such a ferocious creature disposes of during the day. He preys upon the lustrous bluish-green fly, which draws blood almost on the moment of alighting, and also on the sluggish "march" fly, which goes about the business of blood-sucking in a lazy, dreamy, lackadaisical style; and I am inclined to acknowledge him as a friend and as a blessing to humanity generally.
A TRAGEDY IN YELLOW
Quite a distinct tragedy occurred the other day. The little yellow diurnal moth commonly known as "the wanderer" has a partiality for the nectar of the "bachelor's button," as yellow as itself. The morning was gay with butterflies. A "wanderer" poised over a yellow cushion fluttered spasmodically, and remained fixed and steadfast with tightly-closed wings. It allowed itself to be touched without showing uneasiness, and when a brisk movement was made to frighten it to flight it was still steady as a statue. Closer inspection revealed the cause. The body was tightly-gripped in the mandibles of a spider, a yellow rotund spider with long, slender, greeny-yellowy legs. Under cover of the yellow flower the yellow spider had seized the yellow moth. A general inspection showed that the tragedy was almost as universal as the flowers. There were few flowers which did not conceal a spider, and few spiders which had not murdered a moth. The conspiracy between the flower and the spider for the undoing of the moth (a conspiracy from which both profited) was repeated thousands of times this bright morning, and it illustrated the profundity of Nature's lesser tragedies, the sternness with which she adjusts her equilibriums.
COLOUR EFFECTS
A favourite food of the great green, gold and black butterfly (ORNITHOPTERA CASSANDRA) is the nectar of the hard, dull-red flowers of the umbrella-tree, and this fact assisted in an observation which seems to prove that plants play tricks on insects. Among the introduced plants of the island is one of the acalyphas. Butterflies which have feasted among the umbrella-trees on the beach and on the edge of the jungle flit about the garden and almost invariably visit the red but nectarless acalypha. One began at the end of the row, examined the topmost leaves, flitted to the next, and so on, lured by the colour and disappointed by the absence of nectar, twenty-five times, in succession, until it blundered on the red hibiscus bushes and began to feed.
The gorgeous blue swallow-tail (PAPILIO ULYSSES) seems to have a fancy for yellow, for it pays frequent visits to the golden trumpets of the tecoma and the alamanda. The living gold of the flowers and the imperial blue of the insect form a sumptuous if everyday scene.