Fig. 303.—Phasma Rossia—male, female, and larva.
Those Orthoptera which we have already mentioned had all their six legs adapted to running, and are called Cursoria. Those which jump, to which we now come, have their hind-legs stronger and thicker, which enables them to leap, and are on that account called Saltatoria. This section comprises three families, which have for their principal types the Crickets, Locusts, and Grasshoppers.
All these insects resemble each other in the disproportion which exists between their hind-legs and the other pairs. Another characteristic which is common to them consists in the song of the males. This song, so well known, which seems to have for its object to call the females, is nothing but a sort of stridulation or screeching, produced by the rubbing together of the wing cases, or elytra. But the mechanism by which this is produced varies a little in all the three kinds. With the Crickets the whole surface of the wing cases is covered with thick nervures, very prominent and very hard, which cause the noise the insect produces in rubbing the elytra one against the other. With the Locusts, there exists only at the base of the elytra a transparent membrane called the mirror, which is furnished with prominent nervures, and produces the screeching noise. And, lastly, in the Crickets the thighs and elytra are provided with very hard ridges. The thighs, being passed rapidly and with force over the nervures of the elytra, produce the sound, in the same way as a fiddle-bow when drawn across the strings of a violin. In all these insects the male alone is endowed with the faculty of producing sound.
The Crickets and Grasshoppers have very long and thin antennæ, whilst the Locusts have short antennæ, and either flattened or filiform, or swelling out at one extremity like a club. The female of the first two is provided with an ovipositor in the shape of an auger.
We will study successfully the three types of these families, that is to say, the Crickets, the Locusts, and the Grasshoppers.
The Field Cricket (Gryllus campestris, [Fig. 304]) lives alone in a hole which it digs in the ground, and in which it remains during the day. It only quits its retreat at night, when it goes in search of food. It is very timid, and at the least noise ceases its song. If it is stationed on the side of its hole, it retreats into it the moment any one approaches.
The holes of the crickets are well known to country children, who take these insects by presenting a straw to them. The pugnacious cricket seizes it directly with its mandibles, and lets itself be drawn out of its hole. It is this which has given rise to the saying, "plus sot qu'un grillon" (a greater fool than a cricket). It is very susceptible of cold, and always makes the opening of its hole towards the south. It lives on herbs, perhaps also on insects.
The House Cricket is about half an inch long, of an ashy colour, and is to be met with principally in bakers' shops and country kitchens, where it hides itself during the day in the crevices of the walls or at the back of the fireplaces. It eats flour, and also, perhaps, the little insects which live in flour.