THE COLEOPTERA OR BEETLES 55 



among the Hemiptera, are frequently to be seen darting 

 about in groups at the surface of the water. Below the 

 water live the Dystiscidae which are active, predatory 

 creatures, furnished with legs especially fitted for swim- 

 ming. They come to the surface for air, and carry more 

 or less air down with them under their wing cases. The 

 larvae have slender bodies and long, sharp jaws which are 

 perforated, a device that enables them to suck the juices 

 out of the forms on which they prey. Some other large 

 water beetles (Hydrophilidae) live upon decaying vege- 

 table material as well as animal food. 



FIG. 48. The Plum curculio, Conotrac.helus nenuphar, a, larva; 6, pupa; 

 c, adult; d, weevil attacking young plums. 



The snout beetles constitute a peculiarly specialized 

 group, the head being prolonged into a snout which is 

 often of considerable length. The very small mouth parts 

 are situated at the end of this projection and the antennae 

 are borne on its sides. The group is a large one and in- 

 cludes forms known as curculios, and weevils, although the 

 latter term is applied to some small beetles belonging 

 to other families. The snout beetles are particularly 

 destructive to fruits, grains, nuts, and to many other ar- 

 ticles of food. 



