The larvæ of some Australian insects form the most curious nests we have ever beheld. A representation, taken from specimens in the entomological collection at the British Museum, will show what extraordinary structures these are. They appear like minute bundles of faggots, and have been formed by the insect cutting short pieces of twigs, all nearly of the same size, and then cementing them together in the manner represented. Some of these are of a large size, as large as a moderate-sized pear; others are smaller, and these present the most beautifully regular appearance, consisting of a number of very small rods, bound together in a cylindrical form, like the fasces of the Roman soldiery.
Australian Larva-cases.
In this manner larvæ pass through the winter. Without a doubt many perish; but there remain infinite numbers at the end of this season, which, from the depths of their cells, become sensible to the influence of spring, so soon as the first footsteps of that season are felt upon the earth. The larva wakens to active life once more; and with an appetite rendered all the keener by its fast of four or five months, it leaves its dormitory, and begins to consume whatever suitable food may lie in its way; and so it continues, until the time of its change approaches.
PREPARATION FOR A CHANGE.
The last stage of the larva's history hastens on. Its career of activity and voracity is nearly ended, and the insect's days in this form are well nigh spent. Hitherto it has been an earthly, earth-loving being, without either the desire or the power to raise itself into the airy element, in which multitudes of its species are disporting the day long. If we may so speak, its highest desires have only been confined to the quality and quantity of its food; possessing these, it was content. But now, its hours of feasting are come to a close, and it has to make ready for a great and momentous change. The crawling, and, perhaps, repulsive creature which we turn from without regret, has a high destiny to accomplish, when the period of its sojourn in its vile body is fully accomplished; and then, that form which now creeps among the dust of the world, shall mount up as on eagles' wings, and be carried whither it will through the pure regions of the sky.
The age to which the larva generally attains before this change takes place is exceedingly variable. To some it is permitted to reach the venerable age of four or five years; others, three; and many, not nearly so much. The dung and fungus-feeding insects, as if hastened forward by the warmth of their position, are at the end of their larva life in a week; others live a fortnight in this state; and others, several months. We are told of a curious anecdote of a beetle which had existed in a desk, set up in an office in London, for upwards of twenty years, half of which period, according to Messrs. Kirby and Spence, it must have lived as a larva. But this is quite an exception to the general rule.