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CHAPTER II. 



ORDER COLEOPTERA CARNIVOROUS BEETLES. 



Definition of the Order Functions of the Coleoptera in Nature Total Number of Existing Species External Structure 

 Metamorphosis and Early Stages Instincts Voice-organs and Organs of Hearing Hidden Nature of the Haunts 

 of the Majority of the Species of Coleoptera Nocturnal Habits Attracted by Light The Number and Variety of 

 Species swept down by Floods in River- valleys Fossil Beetles Section PENTASIEKA, Beetles with Five-jointed 

 Tarsi Tribe ADEPHAGA, or Predaceous Beetles Family CICIXDELID.E, or Tiger Beetles Family CARABID/E, 

 Carnivorous Ground Beetles. 



THE order Coleoptera embraces that large section of the insect tribes known under the name of 

 Beetles, in which the anterior, or upper, pair of wings are converted into horny covers, or sheaths, 

 meeting in repose in a straight suture down the back, and protecting the posterior, or membranous 

 pair of wings, which, when not in use, lie folded beneath them. Further distinguishing characters 

 are supplied by the mandibulate mouth, adapted for masticating food, and the complete metamorphosis 

 which the individual insects undergo in their growth from the larva to the adult stage. These 

 three important characters, in combination, effectively distinguish all members of the order from 

 the Hemiptera and Orthoptera, which have a superficial resemblance to Beetles in the anterior wings 

 being also more or less indurated, and serving as protecting covers for the membranous wings. 

 Cockroaches, mistaken for " Blackbeetles " by the ignorant, have scarcely anything in common with 

 the true Beetles, and belong to the order Orthoptera. On the other hand, the Lady-bird, the 

 Turnip-fly, and the Glowworm, in which similar superficial observation is apt to fail to recognise the 

 likeness to Beetles, truly belong to this order. The wingless female of the Common Glowworm, and 

 some few other apterous species, are only cases of arrested or retrograde development. 



The compact form and solid integuments which are the rule in Coleoptera adapt them for a far 

 greater diversity of modes of life than is enjoyed by other orders of insects, and especially for plying 

 their vocations in hidden situations ; their relative strength and protective armour enabling them to 

 gnaw or force their way out of the interior places where they have passed their larva and pupa stages. 

 They may be said to perform the function in Nature of universal scavengers, chiefly with regard to 

 the smaller quantities of animal and vegetable matter neglected by the larger animals, but not always, 

 their small size and very varied forms and instincts enabling them to attack, by methods impossible to 

 other animals, and to clear from the earth's surface, the carcases even of large quadrupeds and the 

 dead trunks of the largest forest trees. Different groups are organised respectively for terrestrial and 

 aquatic life, and for every shade of variety in each ; for living in or feeding on vegetable substances, 

 from the smallest cryptogams, to the root, bark, wood, fruit, and seed of the highest forms of 

 vegetation ; and for disposing of excrementitious as well as dead animal substances. All forms of 

 locomotion are displayed ; many are specially adapted for burrowing, and for such curious operations 

 as sawing branches or drilling holes in solid wood. There are predaceous groups terrestrial, 

 arboreal, and aquatic and groups parasitic on the living bodies of other insects ; there are separate 

 sets of alpine, forest, field, and desert forms, in almost every climate, and there is a special Beetle 

 fauna inhabiting the remotest recesses of limestone caverns. In size, Beetles present all gradations, 

 from a length of one-thirtieth of an inch to half a foot. 



Such being the wide range in modes of existence, and the consequent diversity of adapted forms, 

 it is not to be wondered at that the number of species of Coleoptera is very large. No fewer, indeed, 

 than 80,000 species have been already described, and all our larger collections contain many that are 

 still unpublished. It is estimated by Professor Westwood that the total number existing in Nature 

 is not less than 100,000 ; this one order of insects is therefore nearly ten times as numerous as the 

 whole class of Birds, and more than double the whole of the Yertebrata. The classification of the 

 order has been the object of study of many able entomologists since the days of Latreille, who applied 

 the natural system, founded by Jussieu in Botany, to the Insecta. The more recent systernatists 

 have grouped the host of forms under seventy-five natural families. In the present work, whilst 

 adopting these well-defined groups, we have, for convenience, restored the larger divisions of Latreille, 

 founded chiefly on the number of joints in the tarsi, or feet, and the form of the antennae, parts of 

 the mouth, and the habits. 



