In modern warfare, and especially during sieges, the trench is largely used, and is constructed on the most scientific principles, so as to shelter the assailants, while enabling them to proceed nearer and nearer to the fortress. A portion of one of these trenches is shown in the right hand of the illustration.
On the opposite side of the same illustration is shown the same principle as carried out in Nature.
There is a certain little insect, called the Wax-moth, or Galleria-moth (Galleria alvearia), which, although quite harmless in its perfect form, is in its larval state extremely injurious to beehives.
The mother moth contrives, aided by her tiny form and sombre colouring, to slip past the sentries at the mouth of the hive, and to lay her eggs among the combs. This done, she dies, but the evil of her visit lives after her.
Each of the eggs is hatched into a little caterpillar, having a soft grey body, but a hard, horny head of a black-brown colour. As soon as they are hatched they begin to feed, eating not only the waxen combs, but the honey and the bee-bread which were intended for the support of the legitimate inhabitants.
The reader may ask why the bees do not destroy this marauder on their premises. They would be only too glad to do so, but they cannot touch it. As it eats its way along, it constructs a strong silken tube, within which it lives, and which it gradually lengthens. This tube or gallery is exceedingly tough, and perfectly capable of resisting the bee’s sting. Moreover, the caterpillar traverses its tube with such rapidity that the bee has no chance of knowing whereabouts the caterpillar may be when it makes its attack. When it feeds it only protrudes its armed head, the horny covering of which is an effectual protection against the sting.
When these creatures fairly get hold of a hive, the damage which they do is terrible, the whole of the combs being enveloped in the ever-increasing labyrinth of tubes. Even the bees themselves fall victims to the Galleria-moth, for the silken tunnels are driven through and through the combs, enveloping the broad cells as in the meshes of a net. Consequently, when the young bees are developed, they cannot escape from their cells, and perish miserably.
Nor do these tiresome insects confine themselves to hives; but they have an extraordinary facility for discovering bee-combs after they are removed from the hive. Some years ago I was making a collection of various insect habitations, and had brought together a carefully selected set of combs, showing the internal structure of the hive, and the different cells which are inhabited by the worker, the drone, and the queen bee.
One day, when about to arrange the collection in a glass case, I found that the whole of the combs had been destroyed by the Wax-moth. Scarcely a square inch of comb remained, and the contents of the box were little more than a congeries of Wax-moth galleries. Even the Wasp and Hornet nests which had been placed in the same box had been attacked, and, although they had not been so utterly destroyed as the waxen cells, they had been sufficiently injured to render them unfit for exhibition.