PHYLUM ARTHROPOD A 



363 



FIG. 302. Order COLEOPTERA. Novitts cardi- 

 nalis, Australian ladybird beetle, feeding on the 

 fluted scale, Icerya purchasi. a, ladybird larvae 

 feeding on adult female and egg sac ; b, pupa ; 

 c, adult ladybird ; d, orange twig, showing scale 

 and ladybirds natural size. (From Marlatt.) 



Some of the worst 

 pests are the locust 

 borer, Cyllene robinicB, 

 the apple tree borer, 

 Saperda Candida, and 

 the sugar maple borer, 

 Plagionotus speciosus. 

 A common species, 

 Tetraopes tetraophthal- 

 mus, is found on milk- 

 weed. 



SUBORDER 6. TRI- 

 MERA. (LADYBIRD 

 BEETLES, Fig. 302.) 

 The COCCTNELLID.E, 

 or ladybird beetles, 

 are predaceous, both 

 as larvae and adults, 

 feeding largely on plant-lice and scale-insects. They are conse- 

 quently beneficial since they help control these pests (see p. 347). 

 SUBORDER 7. HETEROMERA. (DARKLING, BLISTER- AND OIL- 

 BEETLES, Fig. 303.) The HETEROMERA contains the darkling 

 ground-beetles (TENEBRIONID^E) , one of which, the meal-worm, 



Tenebrio molitor (Fig. 303), 

 is quite common in mills 

 and grocery stores and is 

 used as food for cage 

 birds. This group also 

 includes the blister- and 

 oil-beetles (MELOID^E) ; 

 some of these when dried 

 and pulverized have a 



FIG. 303. Order COLEOPTERA. Meal- blistering effect when 

 worm , Tenebrio molitor. A, larva. B pupa applied to the human 

 C, adult. (From the Cambridge Natural 

 History.) 



skin. 



