[Illustration: _The Larva of a Wasp in its coat of wings and limbs._]
Perhaps the carnivorous larva of the tiger-beetle, or _cicindela_, is as ferocious a being as any in this state. In this respect, indeed, it resembles the perfect insect, whose title sufficiently indicates its swiftness, cunning, and blood-thirsty nature. "These larvæ," writes Mr. Westwood, "burrow cylindric retreats in the earth, to the depth of a foot or more, employing their legs and jaws in loosening the particles of sand and earth, which they carry to the surface upon their broad, saucer-like head, ascending by the assistance of the two hooks upon the back, somewhat after the fashion of a sweep going up a chimney! Having completed this burrow, they station themselves, by means of their legs and back hooks, at its mouth, their large flattened head and great segment filling the hole." Here they remain all day long, and many an insect might pass close by, little dreaming of the terrible foe who lay under that trap-door. Presently comes a spider scrambling over the ground in haste to mount up a branch on which to hang one of its web lines; the treacherous trap-door is in its direct path. Its feet rest on it; instantly the trap drops, and the poor insect falls into the dark den, and is caught in the powerful jaws of the artful larva. Truly, there is something even to man a little intimidating in the sight of such a monster as is represented here; how much more to the unfortunate insect who happens to be caught in its embrace, and having only time to just catch a glimpse of its fearful captor, is dragged down in a cloud of dust to be devoured in darkness at the bottom of the den. Yet this also, like other cruel creatures, is in reality a very timid larva, and instantly on the approach of danger, drops to the bottom of the cell, where, if we have courage to pursue it, we shall find it much in the attitude in which it is here represented. The singular pair of hooks on its back are used as the flukes of an anchor to sustain the insect in the position it assumes at the mouth of the cell.
[Illustration: _Larva of the Tiger-Beetle._]
Mention has already been made in the previous chapter of the insects called Ichneumons, which deposit their eggs in the bodies of the larvæ of other insects. These, when hatched, are also to be reckoned among the larvæ which prey upon flesh, since they devour the bodies of the larvæ in which they have been deposited. They are thus most useful to mankind in destroying the devourers of his vegetable food.