the Frog-hopper or Flea-Locust, Plate LXXIX, in zoology, a genus of insects belonging to the order of hemiptera. The beak is inflected; the antennae are fetaceous; the four wings are membranaceous and deflected; and the feet, in most of the species, are of the jumping kind. The species are fifty-one. The larvae of several of this genus evacuate great quantities of a frothy matter upon the branches and leaves of plants, in the midst of which they constantly hide, probably for shelter against the search of other animals, to which it would become a prey. Nature has afforded this kind of defense to insects whose naked and soft bodies might otherwise very easily be injured; perhaps also the moisture of this foam may serve to screen it from the sultry beams of the sun. On removing the foam, you discover the larva concealed underneath; but it does not long remain uncovered. It soon emits fresh foam, that hides it from the eye of observation. It is in the midst of this foamy substance the larva goes through its metamorphosis into a chrysalis and perfect insect. Other larvae, whose bodies are not so soft, run over plants without any manner of defense, and escape from insects that might hurt them, by the nimbleness of their running, but especially of their leaping.

The chrysalids, and all the larvae that produce them, differ little from each other, only that the former have the rudiments of wings, a kind of knob at the place where the wings will afterwards be in the perfect insect. As to other respects, the chrysalids walk, leap, and run over plants and trees; as do the larva and the frog-hopper, which they arc to produce. At length they throw off their teguments of chrysalids, slip their last slough, and then the insect appears in its utmost state of perfection. The male alone is then endowed with the faculty of singing, which it exercises not with its throat, but with an organ situated under the abdomen. Behind the legs of the male are observed two valvulae, which, raised up, discover several cavities, separated by various membranes. The middle contains a fealy triangle. Two vigorous muscles give motion to another membrane, which alternately becomes concave and convex. The air agitated by this membrane, is modified within the other cavities; and by the help of this sonorous instrument, he amorous solicits his female. By pulling the muscles of a frog-hopper lately dead, it may be made to sing. This insect begins its song early in the morning, and continues it during the heat of the noon-tide sun. Its lively and animated music is, to the country country people, a presage of a fine summer, a plentiful harvest, and the sure return of spring. The cicadae have a head almost triangular, an oblong body, their wings falligated or in form of a roof, and fix legs with which they walk and leap pretty briskly. In the females, at the extremity of the abdomen are seen two large laminae, between which is inclosed, as in a sheath, a spine, or lamina, somewhat ferrated, which serves them for the purpose of depositing their eggs, and probably to sink them into the substance of those plants which the young larvæ are to feed upon.