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CHAPTER VIII.

LEAF-ROLLING CATERPILLARS.

THE labours of those insect-architects, which we have endeavoured to describe in the preceding pages, have been chiefly those of mothers to form a secure nest for their eggs, and the young hatched from them, during the first stage of their existence. But a much more numerous, and not less ingenious class of architects, may be found among the newly-hatched insects themselves, who, untaught by experience, and altogether unassisted by previous example, manifest the most marvellous skill in the construction of tents, houses, galleries, covert-ways, fortifications, and even cities, not to speak of subterranean caverns and subaqueous apartments, which no human art could rival.

The caterpillars, which are familiarly termed leafrollers, are perfect hermits. Each lives in a cell, which it begins to construct almost immediately after it is hatched; and the little structure is at once a house which protects the caterpillar from its enemies, and a store of food for its subsistence while it remains shut up in its prison. But the insect only devours the inner folds. The art which these caterpillars exercise, although called into action but once, perhaps, in their lives, is perfect. They accomplish their purpose with a mechanical skill, which is remarkable for its simplicity and unerring success. The art of rolling leaves into a secure and immoveable

cell may not appear very difficult;-nor would it be so if the caterpillars had fingers, or any parts which were equivalent to those delicate and admirable natural instruments with which man accomplishes his most elaborate works. And yet the human fingers could not roll a rocket-case of paper more regularly than the caterpillar rolls his house of leaves. A leaf is not a very easy substance to roll. In some trees

't is very brittle. It has also a natural elasticity,a disposition to spring back if it be bent,-which is caused by the continuity of its threads, or nervures. This elasticity is speedily overcome by the ingenuity with which the caterpillar works; and the leaf is thus retained in its artificial position for many weeks, under every variety of temperature. We will examine, in detail, how these little leaf-rollers accomplish their task.

One of the most common as well as the most simple fabrics constructed by caterpillars, may be discovered during summer on almost every kind of bush and tree. We shall take as examples those which are found on the lilac, and on the oak.

A small but very pretty chocolate-coloured moth,

Lilac-tree Moth. (Lazotonia Ribeana, STEPHENS ?)

abundant in every garden, but not readily seen from its frequently alighting on the ground which is so nearly of its own colour, deposits its eggs on the leaves of the lilac, and of some other trees, appropriating a leaf to each egg. As soon as the caterpillar is hatched, it begins to secure itself from birds and predatory insects by rolling up the lilac leaf into

the form of a gallery, where it may feed in safety We have repeatedly seen one of them when just escaped from the egg, and only a few lines long, fix several silk threads from one edge of a leaf to the other, or from the edge to the mid-rib. Then going to the middle of the space, he shortened the threads by bending them with his feet, and consequently pulled the edges of the leaves into a circular form; and he retained them in that position by gluing down each thread as he shortened it. In their younger state, those caterpillars seldom roll more than a small portion of the leaf; but when farther advanced, they unite the two edges together in their whole extent, with the exception of a small opening at one end, by which an exit may be made in case of need.

Another species of caterpillar, closely allied to this, rolls up the lilac-leaves in a different form, beginning at the end of a leaf, and fixing and pulling its threads till it gets it nearly into the shape of a scroll of parchment. To retain this form more securely, it is

not contented, like the former insect, with threads fixed on the inside of the leaf; but has also recourse to a few cables which it weaves on the outside.

Another species of moth, allied to the two preceding, is of a pretty green colour, and lays its eggs

Small green Oak-moth. (Tortrix Viridana.)

upon the leaves of the oak. The caterpillar folds them up in a similar manner, but with this difference, that it works on the under surface of the leaf, pulling the edge downwards and backwards, instead of forwards and upwards. This species is very abundant,

Nests of oak-leaf-rolling Caterpillars.

and may readily be found as soon as the leaves expand. In June, when the perfect insect has appeared, by beating a branch of an oak, a whole shower of these pretty green moths may be shook into the air.

Among the leaf-rolling caterpillars, there is a small dark-brown one, with a black head and six feet, very common in gardens on the currant-bush, or the leaves of the rose-tree. (Lozotania Rosana, STEPHENS.) It is exceedingly destructive to the flower-buds. The eggs are deposited in the summer, and probably also in the autumn or in spring, in little oval or circular patches of a green colour. The grub makes its appearance with the first opening of the leaves, of whose structure in the half-expanded state it takes advantage to construct its summer tent. It is not, like some of the other leaf-rollers, contented