There is no other Orthopteron in which the phonetic organs are so complex as they are in the male of Methone anderssoni, and it would appear probable that this Insect possesses the power of producing two, if not more, distinct sounds, one in common with the female, and peculiar to this and one or two other species; the other somewhat similar to that of other Acridiids, and more specially developed in the male, if not absolutely confined to it.
This Insect is of a very sedentary disposition, and when disturbed apparently seeks safety rather by the noise it can make than by flight. Its powers of locomotion indeed are very feeble. The alar organs are quite rudimentary, and of no assistance whatever for movement. The hind legs seem to be almost equally useless for this purpose; they are broader than they are in other Acridiidae, and have different functions. When Methone moves it does so by means of the anterior four legs, on which it walks propped up as if on stilts. When at rest the hind legs are pressed close to the body, and the tibiae are inflexed and not seen, the creature in this position greatly resembling a clod of earth. We know nothing of the life history of this Insect, except that the young resemble the adult in appearance, and are provided with the sound-producing apparatus, or some portion thereof.
The geographical distribution of the Eremobiens corresponds with that of the Pamphagides, with two important differences, viz. that in the Old World the former group occupies a somewhat more restricted area, and that it is represented in the New World by two peculiar North American genera, Haldmanella and Brachystola. B. magna is an Insect nearly equal in size to Methone anderssoni. Its peculiar form and movements have procured for it in Texas and Colorado the popular names of "buffalo hopper" and "lubber grasshopper." This Insect has not—like Methone—the colours of the desert sands; it is of a green tint, with comparatively smooth body, and during the day rests concealed under tufts of grass. It has apparently no sound organs, though de Saussure thinks there are structures present that are vestiges or rudiments thereof.
The family Acridiidae includes a large part of the species that make up our meagre list of British Orthoptera. Indeed, the only native Orthoptera at the present time sufficiently common to attract general attention are, in addition to the earwig, the species of the genera Stenobothrus and Gomphocerus, whose musical instruments we have described previously. We have eight species of these Insects. They are the little grasshoppers, so common in our fields and gardens, the hunting of which is a source of much amusement to children. The Insect goes off with a sudden and long hop just as it is going to be seized, and this is appreciated by the child as very clever. The hunt, as a rule, does not result in much damage to the grasshoppers, the ingenious escape being the greater part of the pleasure. These Stenobothri are remarkable for their variation in colour, and it is thought by some that they frequent spots where they find themselves a match with their surroundings. There is, however, little or no information of importance on this point extant. Mecostethus grossus (Fig. 173), though larger, is very like the common field grasshoppers, but appears to have become rare since the fens were drained. The two curious little grasshoppers of the genus Tettix (Fig. 179) are not uncommon. In addition to these Acridiidae, three species of migratory locusts are occasionally met with in Britain, viz. Pachytylus cinerascens (Fig. 177), P. migratorius, and Schistocerca peregrina (Fig. 84); this latter we have already alluded to as being probably the locust mentioned in the book of Exodus.
Acridiidae have never been found in amber, owing possibly to their large size and strength. There are but few fossil forms known, and these do not extend farther back in time than the Mesozoic epoch. Several forms, including three peculiar genera, have been found in the Tertiary strata at Florissant. The remains from the Mesozoic layers are apparently very fragmentary and obscure.
Brongniart has instituted a family of Insects under the name Palaeacrididae[[242]] for some fossil Insects from the Carboniferous strata at Commentry. He considers that these Insects were abundant in the epoch of the Carboniferous strata.
The very large number of genera and species of Acridiidae have been recently arranged in nine tribes by Brunner von Wattenwyl:—
1. Feet without a claw-pad.[[243]] [Pronotum covering all the body.] Tegmina lobe-like. Tribe 1. Tettigides. (Figs. 179, 180, Tettix, Xerophyllum, Cladonotus.)
1′. Feet with a claw-pad.
2. Antennae shorter than the anterior femora.