Homoptera, impresses the mind with the high importance of these structures to the males, for the sake of calling or alluring the females. We need feel no surprise at the amount of modification which the Orthoptera have undergone in this respect, as we now know, from Dr. Scudder's remarkable discovery,[1] that there has been more than ample time. This naturalist has lately found a fossil insect in the Devonian formation of New Brunswick, which is furnished with "the well-known tympanum or stridulating apparatus of the male Locustidæ." The insect, though in most respects related to the Neuroptera, appears, as is so often the case with very ancient forms, to connect the two related Orders of the Neuroptera and Orthoptera.
I have but little more to say on the Orthoptera. Some of the species are very pugnacious: when two male field-crickets (Gryllus campestris) are confined together, they fight till one kills the other; and the species of Mantis are described as manœuvring with their sword-like front-limbs, like hussars with their sabres. The Chinese keep these insects in little bamboo cages, and match them like game-cocks.[2] With respect to colour, some exotic locusts are beautifully ornamented; the posterior wings being marked with red, blue, and black; but as throughout the Order the sexes rarely differ much in colour, it is not probable that they owe their bright tints to sexual selection. Conspicuous colours may be of use to these insects, by giving notice that they are unpalatable. Thus it has been observed[3] that a bright-coloured Indian locust was invariably rejected when offered to birds and lizards. Some cases, however, are known of sexual differences in colour in this Order. The male of an American cricket[4] is described as being as white as ivory, whilst the female varies from almost white to greenish-yellow or dusky. Mr. Walsh informs me that the adult male of Spectrum femoratum (one of the Phasmidæ) "is of a shining brownish-yellow colour; the adult female being of a dull, opaque, cinereous brown; the young of both sexes being green." Lastly, I may mention that the male of one curious kind of cricket[5] is furnished with "a long membranous appendage, which falls over the face like a veil;" but what its use may be, is not known.
- ↑ 'Transact. Ent. Soc.' 3rd series, vol. ii. ('Journal of Proceedings,' p. 117).
- ↑ Westwood, 'Modern Class. of Insects,' vol. i. p. 427; for crickets, p. 445.
- ↑ Mr. Ch. Horne, in 'Proc. Ent. Soc.' May 3, 1869, p. xii.
- ↑ The Œcanthus nivalis, Harris, 'Insects of New England,' 1842, p. 124. The two sexes of Œ. pellucidus of Europe differ, as I hear from Victor Carus, in nearly the same manner.
- ↑ Platyblemnus: Westwood, 'Modern Class.' vol. i. p. 447.
