PHYLUM ARTHROPODA 



361 



FIG. 298. Order 

 COLEOPTERA. Car- 



Natural 



SUBORDER 2. CLAVICORNIA. (CLUB-HORNED BEETLES, 



Fig. 298.) The club-horned beetles have clubbed antennae. 

 They have little in common ; some are 

 aquatic, others terrestrial ; some are pre- 

 daceous, and therefore beneficial; others 

 herbivorous, and consequently harmful; and 

 a few feed on decaying organic matter. 

 Some of the commoner species are known 

 as water-scavenger beetles (HYDROPHILID^E), 

 rove-beetles (STAPHYLINIDAE) , grain beetles 

 (CucujnxE), burying-beetles (SILPHID.E, Fig. 

 298), and larder-beetles (DERMESTID.E). 

 SUBORDER 3. SERRICORNIA. (SAW-HORNED "on-beetle, Siipha 



^ amencana. (From 



BEETLES, Fig. 299.) The saw-horned beetles Davenport, after 

 have saw-like antennae. They comprise the 

 metallic wood borers (BUPRESTID.E) which 

 injure fruit, shade, and forest trees ; the click-beetles (ELATERID.E, 

 Fig. 299), so called because when laid on their backs they are 

 able to spring up with a click; the death-watch beetles (PTINID^E), 



some of which make a ticking 

 sound against the wood in which 

 they burrow; the fireflies and 

 soldier-beetles (LAMPYRID.E) , the 

 former nocturnal and occasion- 

 ally luminous, the latter diur- 

 nal and predaceous ; and the 

 checkered beetles (CLERHXE), some of which devour the larvae 

 of wood-boring insects. 



SUBORDER 4. LAMELLI CORNEA. (BLADE-HORNED BEETLES, 

 Fig. 300.) The blade-horned beetles have antennae whose 

 terminal segments form flat teeth or lamellae. The stag- 

 beetles (LUCANID^E) have received their name because of the 

 peculiar antler-like processes of the males of certain species. 

 The leaf chafers and scavenger-beetles (SCARAB^ID^:) have 

 very different habits, although they belong to one family. The 



FIG. 299. Order COLEOPTERA. 

 Click-beetle. (From Davenport.) 



