INSECTS ORTHOPTERA This order comprises the earwigs {Forficulida) , the cockroaches (Blattidce)^ the common grasshoppers (Acridiida), the long-horned grass- hoppers {Locustid(e), and the crickets {Gryllidce). In Norfolk we have besides the common earwig {Forficula auricularid), two other kinds, namely the small earwig, which is about half the size of the common kind and is frequently to be found flying in the day-time; and Cheli- dura albipennis, which may readily be distinguished from the common earwig by the absence of wings and the straighter and narrower pincers. It is not uncommon in the Norwich district, and may be obtained by beating mixed hedges in the autumn. It is a curious fact that although the common earwig is quite as well provided with wings as its smaller relative, it is very rarely seen on the wing, or found in situations to which it must necessarily have been transported by flight. Earwigs are said to be fond of their young, and the writer has on more than one occasion found a female of the common earwig with a dozen or more small young ones hidden away under a stone. In this case, however, it cannot be said that the young showed any disposition to avail themselves of parental protection, since mother and young promptly dispersed and ran into hiding in different directions. The cockroaches [Blattida) present two groups : the out-door, truly native species, which are small pale insects less than half an inch long ; and the indoor, more or less naturalized species, which are of a dark mahogany brown colour, and in some cases attain a length of more than two inches. The common house cockroach, or so-called ' black- beetle ' [Periplaneta orientalis), is easily known in the male sex by the shape of the upper wings, which appear as if they had been cut off straight across at some distance from the end of the body. In the females the upper wings are small and scale-like, and the lower pair are quite rudimentary. The song or chirp of the grasshoppers {Acridiidce) is of course well known, but it is, perhaps, not so generally known that each kind has its own song, and that it is possible with a little attention to the difference in the sounds produced to distinguish some of the com- mon grasshoppers (Stenobothrus) even when the insects are not in sight. The sound, which is produced by rubbing together the outer face of the upper wing and the inner face of the hind thigh, is the result of a rapid vibration of the upper wing set up by the friction between one or more 89
