CHAPTER V 



COLEOPTERA OR BEETLES 



Order V. Coleoptera. 



Apparently wingless Insects when at rest, but really with four 

 wings ; the elytra, or anterior pair, shell-like, reposing 

 on the back of the body and fitted together accurately 

 along the middle by a straight suture ; the posterior pair 

 membranous, folded together under the elytra. Mouth ivitli 

 mandibles ; lower lip not divided along the middle. Meta- 

 morphosis great and very abrupt ; the larva being a grub or 

 maggot, which changes to a pupa (usually soft) in which the 

 external structure of the perfect Insect is conspicuous. 



COLEOPTERA or Beetles are chiefly distinguished from other 

 Insects by the solidity of their external integument, and by the 

 peculiar nature of the first pair of their alar organs, which do 

 not serve as instruments of flight, but as shells for protecting the 

 upper face of the after-body, which, unlike the other parts, remains 

 as a rule soft and membranous. These modifications of structure, 

 though apparently slight, must be really extremely advantageous, 

 for beetles are the predominant Order of Insects in the existing 

 epoch. They depart from most other Insects in being less aerial in 

 their habits ; therefore, notwithstanding their enormous numbers, 

 they do not meet the eye so frequently as flies, bees, or butter- 

 flies. The parts of the hard outer skeleton are beautifully 

 fitted together, and as their modifications are easily appreciated 

 they offer as fascinating a subject for study as do the skeletons 

 of Vertebrata. The habits of beetles are so extremely varied 

 that it is but little exaggeration to say that Coleoptera are to 

 be found everywhere, when looked for. The number of species 

 at present known is probably about 150,000. Of these some- 

 where about 3300 have been found in Britain. The structure 



