INSECTA 115 



ponds or rivers. Their food consists mostly of small 

 insects which fall into the water. 



Suborder 2. Clavicornia. The club-horned beetles have 

 the antennae swollen at the distal ends. Their habits 

 vary greatly. The water-scavengers (Hydrophilidce), rove- 

 beetles (Staphylindce) , and burying-beetles (Silphidce) do 

 great good by disposing of dead animals. The grain 

 beetles (Cucujidce) are injurious in granaries. The larder- 

 beetles (Dermestidce) are great pests in museums, factories, 

 etc. They eat all sorts of organic substances, but are 

 particularly fond of dry animal remains, such as insects and 

 furs. 



Suborder 3. Serricornia. The saw-horned beetles have 

 serrated antennae. Here belong the metallic wood borers 

 (Bubestridce) which injure trees and logs; the click-beetles 

 (Elateridce), so-called because they can flip themselves over 

 when turned on their backs; the fireflies and soldier-beetles 

 (Lampyridce) ; and others. 



Suborder 4. Lamellicornia. The blade-horned beetles 

 have the distal ends of their antennae flattened. The stag- 

 beetles (Lucanidce) are probably beneficial, as they de- 

 stroy other insects. Their name refers to the peculiar 

 antler-like growths on the heads of the males of some 

 species. The family Scarabceidce contains a number of 

 beetles which fall into two groups as regards habits. The 

 scavenger-beetles eat decaying matter. The tumble-bug 

 is an example. It places its eggs in a ball of manure, which 

 it rolls to some hole and buries. The Sacred Scarabaeus 

 of Egypt belongs in this family. The leaf-chafers are 

 injurious vegetarians; the common June-bug, Lachnos- 

 terna fusca, being an example. This beetle is a biennial. 

 It spends over a year in the ground as a white grub, and 

 hence appears only every third year. 



Suborder 5. Phytophaga. The plant-eating beetles in- 

 clude the long-horned wood-borers (Cerambycidce) and the 

 bean weevils (Bruchidce). The larvae of these insects are 

 able to bore their way through very resistant materials. 



