THE COLEOPTERA PROM A PRACTICAL POINT OP VIEW. 29 



standard applies ouly when speaking of any one group of beetles as 

 compared with the Coleoptera generally. The same expressions will 

 necessarily vary in force when applied to the species of a jjarticular 

 group as compared with each other, accordingly as the species of that 

 group are large or small as comjjared with the rest of the order ; that 

 is to say, a small species of a gToup of generally large-sized insects 

 may be larger than a large species of a small-sized group. 



LARV^ AND PUP^. 



The larvce of the Coleoptera are usually soft whitish grubs ; naked, or 

 with a few scattered hairs ; with a maudibulate mouth not ver^' unlike 

 that of the perfect insects; usually furnished with six short feet and a 

 single terminal proleg, but sometimes wholly footless. They live in se- 

 cluded situations, sometimes in the ground, but oftener in the wood or 

 under the bark of decaying trees, or in putrescent animal substances, 

 and not unfrequently in nuts and seeds, and in the pulp of fruits. They 

 are rarely found exposed to the light of day, and therefore they never 

 exhibit the beauty of coloration, nor the variety of clothing which gives 

 so much interest to the study of the caterpillars, which are the larvas 

 of the moths and butterflies. The larvse of most of the families of 

 Coleoptera are now pretty well known, but owing to the circum- 

 stances just mentioned, they have generally received but little atten- 

 tion from entomologists compared with that which has been bestowed 

 upon the perfect insects. The larvae of the several families will be 

 more iiarticularly described in their proper connections. 



The pupce are rarely inclosed in cocoons, but the larva3, before chang- 

 ing, simply form cells by turning themselves round and round in the 

 earth or rotten wood, in which they usually undergo their metamor- 

 phoses. But some larvie, especially in the families of Curculionidie and 

 Chrysomelidffi, construct regular (jocoons of web, not very unlike those 

 of the nocturnal Lepidoptera, which they attach to the i)luuts upon 

 whi(;h they feed. The legs of the pupte are always free, but they are 

 not used, the insects being dormant and motionless during this stage of 

 their existence. 



THE COLEOPTERA FROM A PRACTICAL POINT OP VIEW. 



In order to show more clearly the connection between scientific and 

 practical entomology, in classifying the Coleoptera we have taken the 

 food-habits of the several species as the basis of classification, it being 

 in the nature of their food, and their methods of obtaining it, that in- 

 sects come into the most important relationship to mankind, whether 

 of an injurious or a beneficial character. We refer to the Coleoptera 

 particularly, because they exhibit a much greater diversity of food- 



