The great green grasshopper is not, however, a very common insect in this country, being principally confined to the south of the island. Another European and British species, _Decticus verrucivorus_, is of about the same length. It receives its name from the custom prevailing among the Swedish peasants of making it bite their warts. This insect, in common with many others of the same family, when at all roughly handled, emits from the mouth a brownish fluid, which is said to possess acrid qualities, and the introduction of this into the warts is supposed to cause their disappearance. [Illustration: Fig. 73.--Truxalis Nasuta.] _Family 6, Locustidæ._--This family, which includes the grasshoppers and true locusts, is easily distinguished from both the preceding families by the character of the antennæ, which are comparatively short. The common English Grasshopper (_Rhammatocerus biguttulus_), whose song must be familiar to every one who has walked through the fields during the summer time, is produced by the friction of the hinder thighs against the wing-cases. The locusts have been celebrated from the dawn of history on account of the terrible ravages which they have committed in various parts of the world; and although many different species have made their appearance in our own country at various times, the climate, fortunately, seems unsuitable for them to live in, and they have, therefore, not been known to breed here. The Migratory Locust (_Ædipoda migratoria_) is perhaps the best known in this country on account of its visits, many stray individuals of which have visited us at different periods. Locusts are known all the world over, in fact, nearly every country has a species peculiar to itself. The most extraordinary accounts are on record of the vastness of the swarms which every now and again invade particular districts. They are said sometimes to absolutely darken the sun. [Illustration: Fig. 74.--Decticus Verrucivorus.] [Illustration: Fig. 75.--Locusta Peregrina.] They clear off everything from the surface of the ground as completely as if the place had been visited by fire. In many eastern countries locusts are relished as articles of food. The distinctive character of the insects comprised in this group is found in the structure of the wings. The anterior pair are of a horny or leathery consistence, but always much shorter than the abdomen. The hind wings, on the contrary, are of large size, and are composed of a very delicate membrane. There is only one family. [Illustration: Fig. 76.--Caloptenus Italicus.] TRIBE III.--EUPLEXOPTERA. _Family 7, Forficulidæ._--The insects of this family present a great uniformity of structure. They are, for the most part, of nocturnal habits, concealing themselves during the day in crevices under the bark of trees, or in the ground under stones and leaves, etc. Their food consists almost exclusively of vegetable substances, and are sometimes very injurious to flowers and fruit.