"Order COLEOPTERA ([Greek: koleos], a sheath; [Greek: pteron], wing). Beetles or Shield-winged Insects. Characterized by having four wings, the front pair (called _elytra_) horny or leathery, and usually united down the back with a straight suture when at rest, the hind ones membranous and folded up under the elytra when at rest. Transformations complete. [Illustration: FIG. 9.--A Chafer, _Cotalpa lanigera_. (After Packard.)] [Illustration: FIG. 10.--A Longicorn, _Saperda candida_. _a_, larva; _b_, pupa; _c_, beetle.] "This is an order of great importance, and in the vast number and diversity of the species comprised in it outranks any of the others. The ease with which the insects of this order are obtained and preserved make it one of the most attractive to the amateur, and beetles are, perhaps, of all insects, the best known and understood in the popular mind. For the same reason they have, in the perfect state, received most attention from the entomologists, but their transformations and preparatory forms yet offer a wide and inviting field for the student. The simplest and best-known classification of the beetles is the tarsal system, founded on the number of joints to the tarsi, by which we get four great sections: (1) PENTAMERA, in which all the tarsi are 5-jointed; (2) HETEROMERA, with the four anterior 5-jointed and the two posterior 4-jointed; (3) PSEUDO-TETRAMERA, with apparently only four joints to all the tarsi, though, in reality, there is a fifth penultimate joint, diminutive and concealed; (4) PSEUDO-TRIMERA, with apparently only three joints to all the tarsi. This system, like most others, is not perfect, as there are numerous species not possessing five joints to the tarsi belonging to the first section; and for practical purposes beetles may be very well arranged according to habit. We thus get, first, the ADEPHAGA, or carnivorous species, including all those which prey on other living insects, and to which, following Mr. Walsh, I have, for obvious reasons, applied the suggestive term 'Cannibal'; second, the NECROPHAGA, comprising those which feed on carrion, dung, fungi, and decaying vegetation; third, the PHYTOPHAGA, embracing all those feeding on living vegetation. This arrangement is by no means perfect, for there are beetles which are carnivorous in the larva and herbivorous in the imago state; while some of the NECROPHAGA are actually parasitic. Yet, it is not more artificial than others which have been proposed. The carnivorous species, broadly speaking, are _Pentamerous_, the only striking exception being the Coccinellidae (Lady-birds), which are _Pseudo-trimerous_. The carrion-feeders are also _Pentamerous_; but vegetable-feeders are found in all the tarsal divisions, though the _Pseudo-tetramera_ are the more essentially herbivorous, and consequently the most injurious."