Coleopiera, or Beetles. 553 



imago. There are, however, some insects which are 

 active throughout their lives, and in these the larvae and 

 pupae are very similar to the perfect insect. The perfect 

 insect is divided into three segments, or parts, called the 

 head, the thorax, and the abdomen. 



ORDER I. Coleoptera, or Beetles. 



THE larva of the beetle is a grub, which often continues 

 in that state three or four years, eating voraciously 

 during the whole period. When full grown it in most 

 cases either descends into the ground, where it under- 

 goes its transformations, first into a nymph, or pupa, and 

 then into a beetle ; or it makes itself a rough cocoon of 

 bits of stick and dead leaves, in which it changes into a 

 pupa, and afterwards into a beetle. The wood-eating 

 beetles undergo their transformations in the tree on 

 which they feed. The pupa of the beetle is termed in- 

 complete, because all the parts of the insect are visible 

 in it, instead of being enclosed in one thick covering, as 

 in the moths and butterflies. The head of the beetle 

 is furnished with two compound eyes; two antennae 

 (differing in shape in the various species, but having 

 usually eleven joints); and a mouth, consisting of a 

 labrum, or upper lip, a labium, or under lip, two man- 

 dibles, or upper jaws, and two maxillae, or under jaws. 

 There is also the mentum, or chin, and a part called the 

 clypeus, to which the upper lip is attached. 



The thorax is the part which supports the legs and 

 wings. The legs are divided into five portions, of which 

 the part terminated by the claw is called the tarsus. 

 There are two membranous wings, covered by two 

 hardened wings or wing-cases, called the elytra, which 

 generally open by a straight line down the back ; and 

 hence the name of Coleoptera, which signifies wing in 

 a case : the abdomen is simply the body. 



The number of beetles is very great, and indeed Mr. 

 Westwood informs us that more than thirty thousand 

 species have been described, of which about three thou- 

 sand five hundred are natives of Britain. 



