On the origin and metamorphoses of insects / by Sir John Lubbock.

Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: On the origin and metamorphoses of insects / by Sir John Lubbock. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    the sawfly, but resembling a needle. With this she stings or punctures the surface of leaves, buds, stalks, or even roots of various plants. In the wound thus produced she lays one or more eggs. The effects of this proceeding, and particularly of the irritating fluid which she injects into the wound, is to produce a tumour or gall, within which the egg hatches, and on which the larva, a thick fleshy grub (Plate II., Fig. 7), feeds. In some species each gall contains a single larva; in others, several live together. The oak supports several kinds of gallflies : one produces the well-known oak-apple, one a small swelling on the leaf, resembling a currant, another a gall some- what like an acorn, another attacks the root ; the species making the bullet-like galls, which are now so common, has only existed for a few years in this country; the beautiful little spangles so common in autumn on the under side of oak-leaves are the work of another species, the Cynips longipennis. When the larva is full-grown, it eats through the gall, falls to the earth, and turns into a chrysalis. One curious point about this group is, that in some of the commonest species the females alone are known, no one yet having ever succeeded in finding a male. Another great family of the Hymenoptera is that of the ichneumons; the females lay their eggs either in or on other insects, within the bodies of which the larvae live. These larvae are thick, fleshy, legless grubs, and feed on the fatty tissues of their hosts, but do not attack the vital organs. When full- grown, the grubs eat their way through the skin of