Order COLEOPTERA. 



The Coleoptera or beetles are recognizable by their hard or leathery 

 wing covers, which are laid over the abdomen so that they meet in a 

 straight line down the back, the hind wings being transversely folded 

 beneath them. They have mandibulate or chewing mouth parts and feed 

 on a great range of substances, animal and vegetable, as well in the larval 

 as in the adult stages. There is no part of plants that is not attacked by 

 some species, hence many are seriously injurious; but, on the other hand, 

 predatory forms occur also in great abundance, and some of these are 

 markedly beneficial. The larvae vary much in shape, but never have more 

 than six functional legs, and their habits are as diverse as those of the 

 adults. The pupal stage is inactive, and the metamorphosis is therefore 

 complete. 



The characters upon which classification is based are found in the num- 

 ber of joints on the feet and in shape of the antennae or feelers, the snout 

 beetles being first separated off by the mouth parts, which are set at the 

 end of a longer or shorter beak. 



It is not usually difficult to determine whether a beetle is probably in- 

 jurious, harmful or beneficial, if a few points of structure are carefully 

 observed. 



First. Practically all weevils or snout beetles are plant feeders and 

 may be or become injurious; none are beneficial. 



Second. All beetles that have only four apparent joints to the feet or 

 tarsi, the third joint lobed or split, are to be looked upon with suspicion, 

 for they are likely to be either leaf beetles, like the potato or asparagus 

 beetle, or wood-borers of the family "Cerambycidae," like the round-headed 

 apple borer. 



Third. Beetles with five-jointed tarsi or feet, and feelers that have a 

 large leaf-like club at tip are likely to be leaf chafers, like the "May- 

 beetle" or "rose-bug," and their larvae are "white grubs," many of which 

 are injurious. A few of these beetles are scavengers and at least harm- 

 less, but none are to be accounted really beneficial. 



Fourth. Beetles with five-jointed tarsi and antennae that are somewhat 

 flattened and have the joints marked like the teeth of a saw are likely 

 to be injurious. If the prothorax is loosely jointed to the rest of the 

 body, they are snapping or click beetles, whose larvae are wire-worms, 

 and this series contains also the Buprestidae or flat-headed borers. 



Fifth. If the antennae are gradually enlarged toward the tip, forming 

 a club, the insects are likely to be scavengers or feeders upon dead or 

 dry animal or vegetable matter; but this is subject to many exceptions, 

 and it is only safe to say that such species are not likely to be feeders 

 upon growing vegetation. 



Sixth. Beetles in which the hind tarsi or feet are 4-jointed, while the 

 others have five joints, are likely to prove feeders in dead or dying wood 



(195) 



