EARWIG, an insect belonging to the family For ficulidae of the order Dermaptera. It is characterized by the very short leathery fore-wings, or tegmina, and the large semi-circular mem branous hind wings which have highly modified veins disposed in a radial manner. When the insect is at rest the hind wings are folded longitudinally in a fan-like fashion: there are also two other folds in a transverse direction and, in this way, they are tucked away beneath the tegmina. The body is terminated by a pair of horny forceps which exhibit evident differences of form in the two sexes. A remarkable fact about them is that the males fall into two sharply marked classes as regards the length of their forceps. It appears that the development of forceps of inter mediate length is very unusual. The significance of this fact is still obscure. These forceps are highly modified cerci and, in the Ceylon genus Diplatys, the immature forms carry long jointed cerci, which are replaced by forceps only at the last moult. The function of the forceps is by no means clear, but in all prob ability they are mainly used as organs of offence and defence : when alarmed an earwig often uplifts the apex of the abdomen with the forceps widely opened in a threatening manner. The origin of the name earwig is uncertain : by some it is believed to be due to the fact that the insect has been known to use the human ear for purposes of concealment, but others claim it is a corruption of earwing in allusion to the form of the hind wings.
For ficulidae is almost cosmopolitan and the best known species is the common European earwig, For ficula auricu laria. This insect is gregarious and nocturnal, hiding by day under loose bark, in hollow stems, under stones or in any suitable dark crevice. At night it becomes active, feeding upon tender foliage, flower petals, fruit, etc., and being especially partial to dahlias. The extent to which it partakes of animal food is un certain but it is known to devour both living and dead insects. It is a curious fact that, in spite of the possession of well-formed wings, this insect has only on very rare occasions been seen to fly : also, the often repeated statement that the forceps assist in folding up the wings needs substantiation. The eggs are laid in masses up to so or more in number. They are deposited in a cavity in the soil where they are guarded by the female earwig, who rests over them until they hatch and the young nymphs are able to shift for themselves. The eggs are found during winter and early spring and the nymphs, after moulting four to six times, become mature during the summer. The European earwig has secured a footing on the Pacific side of N. America as well as in parts of New Zealand. In these localities it has become exceed ingly numerous and destructive. Efforts are being made to con trol the insect by importing certain natural enemies from Europe into those lands which the earwig has adopted. The enemies known to parasitize the earwig are two species of flies of the family Tachinidae whose larvae live within and finally kill their host. Under ordinary circumstances earwigs are usually destroyed by means of traps or poison baits. Plant pots stuffed with straw and inverted on canes are a well known lure : in the United States the broadcasting of a poisoned bran mash bait has been recom mended in places where the insect is very numerous. (A. D. I.)
