THE BEETLES 



141 



i 



are readily recognizable by the front margin of the head extending 

 across the eyes so that there seems to be a pair of eyes on both 



the upper and the under surface. 



The Club-Horned Hectics (Clavicornid) 



The antennae of the beetles of this tribe are either 

 gradually or abruptly thickened toward the tip so as 



to form a club. The 

 common families 

 either live as scav- 

 engers or feed on 

 stored products, 

 but there is a large 

 series of small fam- 

 ilies with the most 

 varied habits, al- 

 though not many 



FIG. 197. A predacious diving-beetle (Dytiscns sp.). i nr i nf ip cnpripQ nf 



I Natural size) 



serious economic 



a, larva, or "water-tiger"; b, pupa; f, adult. (After Kellogg) 



importance. 



The water-scavenger beetles (Hydrophilidae) closely resemble the 

 predacious diving-beetles, but are more convex above and more 

 flattened below, have more highly polished wing-covers, and have 



FlG. 198. Whirligig-beetles (Gyrinidae}. (Natural size) 

 (After Linville and Kelly) 



antennae that are decidedly clubbed, though often concealed beneath 

 the head. They feed on decaying animal and plant tissues, though 

 they not uncommonly catch small insects, and the larvae feed 



