52 OUTLINES OF ENTOMOLOGY. 



Coleopterous larvae feed upon almost all kinds of vegetable and 

 animal substances, from the petals of the most delicate flower to the 

 most rank smelling carrion, from fruits and nuts to the most pungent 

 spices to be found at the grocer's or druggist's. A considerable pro- 

 portion are cannibals, and prey upon members of their own class. 

 LarvsB of such species are usually very active, while the vegetable 

 feeders are, as a rule, awkward and sluggish in their movements. In 

 this Order the transformations are complete. The larvae molt or change 

 their skins several times, and their growing period varies in length 

 from a few weeks to two or three years. They transform either upon 

 or beneath the surface of the ground, or upon the leaves or within the 

 fruit or wood upon which they have fed. The pupae are obtected, re- 

 sembling those of Hymenoptera in having each member encased in a 

 separate sheath. 



In the matter of classification, this Order is so comprehensive, that 

 it is impossible within the limits of this little work to include any sys- 

 tem that will enable the tyro to determine every species of which he 

 may find an example, except as to the primary divisions. Beyond this 

 the most that will be attempted will be a definition oS such groups as con- 

 tain conspicuously injurious or conspicuously beneficial species. When 

 we learn that in North America alone, exclusive of Mexico, we have more 

 than nine thousand named species, representing upwards of seventeen 

 hundred genera and about eighty distinct families, it is evident than 

 volumes are required for anything like adequate description and 

 definition. 



Following the system of the recognized authorities, the primary 

 divisions of the Coleoptera are as follows : 



Sub-Order I. The True Beetles (C o le o PTERi), in which the 

 mouth parts are all present and the front of the head is not elongated. 



Sub-Order II. The Snout Beetles (R h y n c o p h o R a), in which 

 the front part of the head is more or less prolonged into a beak, the 

 labrum not distinguishable and the palpi reduced to minute, jointless 

 points. 



The first of these Sub-Orders is then separated into two sections^ 

 based upon the correspondence or lack of correspondence in the num- 

 ber of tarsal joints. 



Ist. IsoMERA (Similar joints) species which, with rare ex- 

 ceptions, have the same number of joints in all the feet. 



2d. Heteromera (Different joints), including species which 

 have five joints in each of the front and middle feet, and only four 

 joints in each of the hinder pair. 



