THE YOUNG LARVA.
The generality of insects, as has been before mentioned, are destined never to behold the birth of their progeny, nor to experience either the pleasures or the cares of parents surrounded by their families. Their anxieties cease when they have carefully stored up their eggs, and their existence is generally soon afterwards at an end. The insect world, therefore, presents us with but few opportunities of witnessing the display of a parental affection on the part of its members; but, as was mentioned in the conclusion of the last chapter, a few examples of the kind do exist, and, perhaps, the very fact of their being few in number contributes to make them the more interesting to us. We have seen a noble instance of self-devotion on the part of a poor spider in defence of her eggs. Let us now turn to some examples of the love of an insect mother for her young larva. If the reader will carefully search the twigs and leaves of the birch-tree in the month of July he may possibly succeed in finding the little insect, the field-bug, of which mention is about being made, and witness for himself the strange spectacle described in the following account from the great work on insects by De Geer. In order that it may be recognised, we have here adjoined a representation of the insect. Its colour is a greenish gray on the back, dotted all over with very minute black spots; the under portion of the insect is greenish yellow, with black spots. It lives upon the sap of the birch-tree.
The Field-bug.
"The mother," says De Geer, "was accompanied by a troop of little ones, sometimes as many as forty in number. She remained constantly with them, generally on a twig or leaf. I noticed that the little ones and their mother did not always remain in the same place, and that as soon as the mother began to move to another position, all the little ones began to run after her, and stopped whenever the mother halted. She used to take them, as it were, for a walk from twig to twig, or from one leaf to another, parading up and down the branches of the tree, and she conducted them wherever she pleased, just as a hen does her chickens. It frequently afforded me great pleasure to observe their movements. One day I cut a young branch of the birch-tree inhabited by such an insect family, and I immediately saw the mother, apparently in great anxiety, begin to flap her wings violently, but without attempting to fly away, as though she would frighten away her enemy. At another time she would have immediately made her escape, thus plainly showing that she remained only in order to defend her young brood."
As if to furnish an instance of precisely the opposite import, the cruel and murderous father of this interesting little family is one of the greatest enemies the poor mother has to contend against. This hard-hearted parent does not hesitate whenever he falls in with one of his children to seize him and eat him up! If the mother spies him at this horrible feast she immediately attacks him in the manner described; and does her utmost to deter him from his cannibal propensities, by placing herself in an attitude of determined resistance before him. Was ever mother's love more plainly manifested than this love? No other instance of an affection so strange and strong is to be found in the tribe to which she belongs.
The care of the earwig not only extends to her eggs, but also to her young larvæ. "In the beginning of June," writes the author last quoted, "I found under a stone a female earwig, surrounded by a number of little creatures which I discovered to be her tiny family. She did not attempt to leave them, and they frequently ran and crouched under her, just as chickens under the wing of a hen. I took them up and placed them under a sand-glass, under which I had put a little fresh earth. They did not bore into the earth; and it was most curious to see them running for shelter under the mother, and pushing about between her feet, while she remained perfectly quiet. I fed them with pieces of ripe apple, which the mother seized and ate with great avidity, detaching morsels of it by means of her teeth, and swallowing them. The young ones also ate a little of it, but with less avidity."
When the eggs of the spider mentioned in the last chapter as so devotedly attached to its treasure as to prefer death to parting with them, are hatched, they make their way out of the bag by an opening in it, being assisted by the mother in this difficult task. De Geer indeed states that this is the reason why the mother clings so tenaciously to the bag of eggs, as if she knew that her assistance in extricating her young from it was necessary. But this is not altogether correct, as they are able to make their way out by themselves in due time. When the young larvæ have come forth from the shell they run towards the mother, and climb upon her body; some get on her head, some on her back, and some on her limbs. In this manner she carries them about, and is said to feed them until they become strong enough to shift for themselves. "I have more than once been gratified," (writes one of the authors of the Introduction to Entomology,) "by a sight of this interesting spectacle; and when I nearly touched the mother, thus covered by hundreds of progeny, it was most amusing to see them all leap from her back, and run away in all directions."
For another instance of affection almost maternal for the young and helpless larvæ, let us take a peep into an ant's nest. So soon as ever the young larvæ emerge from the eggs they require the unremitting attention of the best and most careful nurses in order to rear them. They must be kept clean, fed, and taken for an airing as regularly as the day returns. By means of their tongues, which are incessantly used in licking them, their coats are kept of the most snowy white. They are fed three or four times a day by their nurses, who take care to masticate the food for them, and thus prepare it for their tender mouths. But the most strange part is their regularly being taken out for the benefit of the air and warmth. Some of the ants at the top of the nest watch for the first beams of the welcome sun, and, as soon as they pour upon the nest, they hasten down below in a great bustle to wake up the nurses, and bid them take the young ones out of their chambers and bring them up to the light, which these indefatigable ants quickly set about to do. After basking there all day long the nurses take care not to expose the delicate constitutions of the larvæ to the chill evening air; and soon as the sun begins to sink towards the horizon they carefully take them up and carry them to the warm deep cell below. For fear, perhaps, of their taking cold, they never allow them to be taken out in raw, damp, or frosty weather. It must not be forgotten, however, that these ants are not the parents of the larvæ; they are only the nurses.