INCLUDING THE GRASSHOPPERS, LOCUSTS, CRICKETS, COCKROACHES, EARWIGS,
AND THEIR ALLIES.
The _Orthoptera_ include all those forms of insects which have
four wings, the anterior pair being of a leathery nature. They are
mandibulate; that is, their mouths are formed for biting, and they
undergo an imperfect metamorphosis.
The insects comprised in this order are extremely numerous and
destructive in the tropical parts of the world (Kirby gives their
number as about 7,000), but they are only represented in the British
Isles by about sixty species, few of which are really abundant. They
include the cockroaches, crickets, grasshoppers, locusts, earwigs, etc.
All these insects may be divided into three sub-divisions or
tribes--namely, the Runners or _Cursoria_, the Leapers or _Saltatoria_,
and the Earwigs or _Euplexoptera_.
The following table will show at a glance the outlines of the proposed
arrangement:--
_Tribe_ I., _Cursoria_.--Hind wings with veins radiating from the
base. Hind legs formed for running.
_Tribe_ II., _Saltatoria_.--Hind wings with veins radiating from base.
Hind legs formed for leaping.
_Tribe_ III., _Euplexoptera_.--Hind wings with veins radiating from
the apex of a horny piece occupying the base of the anterior margin.
The _Euplexoptera_, or Earwigs, are regarded by some authors as a
separate order. They are thus treated by Westwood in his "Introduction
to the Modern Classification of Insects," but the modern tendency is
to revert to the Linnæan system, and retain them among the _Orthoptera_.
[Illustration: Fig. 65.--Phasgonura Viridissima.]