In number of species the Locustidae are perhaps scarcely inferior to the Acridiidae, and in variety of form they surpass this latter family. Many of the most gigantic forms are apterous, and these very often have a repellant aspect. The genus Anostostoma is remarkable for its large head. Allied to it is Deinacrida heteracantha, the "Weta-punga" of the New Zealand natives, an Insect formerly abundant in the forests north of Auckland, but of late years become extremely rare. The head and body of this Insect may measure more than 2½ inches in length, and when the antennae and legs are stretched out the total length may be 14 or 15 inches. Although bulky and absolutely wingless, yet, as Buller informs us,[[255]] it climbs with agility, and is sometimes found on the topmost branches of lofty trees. When disturbed it produces a clicking, accompanied by a slow movement of its hind legs. A second species, D. thoracica, lives in decayed wood, and a third, D. megacephala, is remarkable from the very large size of the head and mandibles in the male sex. The fact that a clicking noise is produced by the Weta-punga is of some interest, for the genus Deinacrida is among the Locustidae that possess ears, but are said to be destitute of sound-producing organs.
Amongst the most remarkable of the Locustidae are the two species of which Brongniart has recently formed the genus Eumegalodon and the tribe Eumegalodonidae, which is not included in Brunner's table of the tribes of Locustidae. The ovipositor is large and sabre-shaped; the male is unknown. The genus Megalodon is placed by Brunner in the tribe Conocephalides; it also consists of extremely remarkable Insects.
Fig. 203.—Eumegalodon blanchardi, female. Borneo. × ⅘. (After Brongniart.)
The Locustidae appear to be of slow growth, and the autumns of Britain are usually not warm enough for them. Hence we have but nine British species, and of this number only three or four are known to occur north of the Thames. The only one that attracts attention is Locusta viridissima, which in some districts of the south of England occurs in considerable numbers, and attests its presence by its peculiar music. It is called the green grasshopper.
The geological record is rather obscure in the matter of Locustidae. Scudder considers that a fair number of Tertiary forms are known, and says that they represent several of the existing tribes and genera. One or two have been found in Mesozoic rocks.
Table of the Tribes of Locustidae
1. Tarsi more or less depressed.
2. Front tibiae furnished with auditory cavities.
3. Antennae less distant from the summit of the occiput than from the labrum; inserted between the eyes.[[256]]