CHAPTER X 



THE COLEOPTERA: BEETLES 



THE Coleoptera comprises those insects which are popularly 

 called Beetles. Their numbers are legion, and something like 

 150,000 species have been collected, of which a great proportion 

 have been described. Considering the amount of attention which 

 the Coleoptera have received, one might think that there was 

 something unusually interesting about them ; but this is not 

 the case, and one can only suppose that the interest they have 

 excited is due to the beauty of some of them, to the curious 

 shape of many, and to the ease with which they may be pre- 

 served. 



Beetles are very readily distinguished from all other insects. 

 The upper pair of wings are always of the same hard texture as 

 the other parts of the body ; they never cross one over the other 

 when the insect is at rest, but meet in a straight suture down 

 the back, and cover the body more or less perfectly. They are 

 sheaths, and act as coverings to the hind pair of large membran- 

 ous wings which lie folded beneath them. The name Coleoptera 

 is taken from this peculiarity (literally, " sheath-winged "), and 

 the sheaths are called elytra. These elytra, when the beetle takes 

 flight, open at right angles with the body and project straight 

 out from it, remaining fixed in that position during flight, and 

 do not beat the air or vibrate, the larger and membranous hind 

 wings being the organs by which the beetle propels itself through 

 the air. The parts of the mouth are generally well developed 

 and strong, and are fashioned for purposes of mastication. All 

 the Coleoptera undergo complete metamorphosis. The larva 

 varies very greatly in form in different families ; it is generally 

 elongated, clothed with a tough skin, and furnished with six feet, 

 but in some groups it is a footless maggot. In all its forms, 

 however, the coleopterous larva has a distinct head, and thus 



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