CHAFER, a word used in modern speech to distinguish the beetles of the family Scarabaeidae, and more especially those species which feed on leaves in the adult state. The word is derived from the O. Eng. ceafor, and it is interesting to note that the cognate Ger. Käfer is applied to beetles of all kinds. For the characters of the Scarabaeidae see Coleoptera. This family includes a large number of beetles, some of which feed on dung and others on vegetable tissues. The cockchafers and their near allies belong to the subfamily Melolonthinae, and the rose-chafers to the Cetoniinae; in both the beetles eat leaves, and their grubs spend a long life underground devouring roots. In Britain the Melolonthines that are usually noted as injurious are the two species of cockchafer (Melolontha vulgaris and M. hippocastani), large heavy beetles with black pubescent pro-thorax, brown elytra and an elongated pointed tail-process; the summer-chafer (Rhizotrogus solstitialis), a smaller pale brown chafer; and the still smaller garden-chafer or “cocker-bundy” (Phyllopertha horticola), which has a dark green pro-thorax and brown elytra. Of the Cetoniines, the beautiful metallic green rose-chafer, Cetonia aurata, sometimes causes damage, especially in gardens. The larvae of the chafers are heavy, soft-skinned grubs, with hard brown heads provided with powerful mandibles, three pairs of well-developed legs, and a swollen abdomen. As they grow, the larvae become strongly flexed towards the ventral surface, and lie curled up in their earthen cells, feeding on roots. The larval life lasts several years, and in hard frosts the grubs go deep down away from the surface. Pupation takes place in the autumn, and though the perfect insect emerges from the cuticle very soon afterwards, it remains in its underground cell for several months, not making its way to the upper air until the ensuing summer. After pairing, the female crawls down into the soil to lay her eggs. The grubs of chafers, when turned up by the plough, are greedily devoured by poultry, pigs and various wild birds. When the beetles become so numerous as to call for destruction, they are usually shaken off the trees where they rest on to sheets or tarred boards. On the continent of Europe chafers are far more numerous than in the United Kingdom, and the rural governments in France give rewards for their destruction. D. Sharp states that in the department of Seine-inférieure 867,173,000 cockchafers and 647,000,000 larvae were killed in the four years preceding 1870.
The anatomy of Melolontha is very fully described in a classical memoir by H. E. Strauss-Dürckheim (Paris, 1828). (G. H. C.)