THE LOCUST AS A SYMBOL.

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what household fires will they not extinguish, leaving desolate hearths and homes behind?

But that Power, who by the bridle of instinct conducts the migratory locust to perish in the waves, has set bounds also to the career of the locust of society. He is not impelled irresistibly, like his insect prototype, to his own destruction; but if he turn not from his course he is borne by the current of vice into the gulf of perdition.

The analogy between locust legions and lovers of guilty pleasure holds good even after death. Cast up by the sea, and left upon the shore-a bank of corruption-the insect remains infect the air, and complete by pestilence their previous work of destruction. And so, when swept by death from the face of society, the moral locust fails not to leave behind the ill odour and pestilential influence of corrupt example.

Thou dosk dance and thou dost sing!"

THERE is a certain destructive tribe of insects which may be seen everywhere; and they may be seen not only now, but at almost every season.

The varied species of insects which compose this tribe differ widely both in magnitude and in strength; but they are, one and all, according to their power, active, prying, and destructive. They are specious in outward form, but they are for ever watching opportunities to make breaches in the citadel of life, that they may introduce therein, sometimes a single assassin, sometimes a murderous host,

which sap its foundations, and bring it, sooner or later, to destruction. The above description (that of parasitic insects) applies almost as exactly to those destructive spirits whose name is Legion, which are for ever seeking the life of the soul; generally, in the first instance (as with their insect prototypes) assailing it singly, but, wherever successful, making way for a multitude of vices, sprung from the original, to complete the work their parent has begun. Our business is not with parasitic vices (except our own), but with parasitic flies. The analogy, however, betwixt the two affords so striking a text of one homily of nature, that, though pointed out before, we note it here, as a comparison to be kept in view, extended, and applied, while we trace the proceedings of a notable few amongst the most insidious of all insect destroyers of insect vitality.

*

Ichneumon is the name generally applied to the parasitic race of which we have been speaking. There are, however, various insects of parasitic habits which are not properly ichneumons, though the name, as signifying pryers, does not ill befit them.

The original ichneumon of antiquity was, as most people are aware, no insect at all, but a little four-footed animal, a pryer after, and devourer of, crocodiles' eggs, on which account it was adored by the deifying people of Egypt as among their benefactors; and amongst ours we are bound, certainly, to rank its insect namesakes, prying, as they do,

* By Kirby.

for our benefit, after caterpillars in the egg as well as in

maturity.

But the extensive value of ichneumons, as a check upon caterpillar depredation, may be best estimated by their numbers, of which we may form a tolerable notion when we hear of above 1,300 species* in Europe only, some so minute "that the egg of a butterfly is sufficient for the support of two [individuals] until they reach maturity; others so large that the body of a full-grown caterpillar does not more than suffice for one."+

Aristotle is said to have first applied the name of Ichneumon to the wasp; and certain wasps there are, betwixt whom and ichneumon-flies, properly so called, there is not a pin to choose, as regards their prying parasitic habits. The ichneumons belong also to the same order (that of Hymenoptera) as wasps and bees; both, spite of their relationship, among the objects of their treacherous attack.

Of this distant kinship there are outward traces in the four transparent wings, and in the slight wasp-like attachment of the ichneumon's breast and abdomen, also in its prevailing colours of black and orange; but the ichneumon, whether a dwarf or a giant of its family, has a figure of such peculiar cut as to make it easy enough, when acquainted with one, to recognize a hundred of his name. We may know them by their long narrow bodies, so convenient for prying and poking into holes and corners, as well as by their long, flexible, jointed horns, *Naturalist's Library.' Kirby and Spence, Introduction.

ICHNEUMON BORERS.

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so continually on the vibrate as to have procured for their possessors the appellation of Musca vibrantes. With these organs* (supposed to combine the uses of feelers and of ears) our pryers are to be seen for ever exploring, both by touch and hearing, the places and the living subjects best suited to receive

their eggs.

Cuckoo-flies is another appellation by which ichneumons are distinguished, because, like the cuckoo, they are accustomed, lazily, intrusively, dishonestly, and cruelly, to deposit their eggs in stranger nests—sometimes within stranger eggshells-sometimes within the bodies of stranger grubs and caterpillars, either in their infancy or when they have attained their growth. For execution of these her nefarious practices, the female ichneumon is provided with a very conspicuous instrument, tail-like, seeming composed sometimes of one, sometimes of three divergent hairs, but consisting, in fact, of a single ovipositor, or borer, with a sheath longitudinally divided and opening like a pair of compasses. The nicest adaptation marks this curious instrument, which, according to the different species and habits of its possessor, is employed to pierce, sometimes only an exposed egg, sometimes the skin of a grub, caterpillar, or chrysalis, and sometimes through defences strong and deep, coverings of silk, or wood, or clay; and, according to these varied requisitions, it is shorter or longer, thinner or thicker, stiffer or more pliant. In one large

* Antennæ.