INSECTS ATTACKING GARDEN VEGETABLES. 



TORTOISE BEETLES. 

 (Species of Cassida and Coptocycla; Order, Coleoptera.) 



Diagnosis. Attacking sweet - potatoes ; small, turtle - shaped 

 beetles, some of them with bright, metallic tints, feeding on the 

 leaves ; or the larvae ( young ) of these beetles, in general shape 

 like the beetles, broad and flattened, but the margin of the body 

 armed with spines, feeding on the leaves. 



Description and Life-history. There are a half-dozen species 

 of these Tortoise Beetles, belonging to the genera Cassida and 



a 



FIG. 27. TORTOISE BEETLES; n, larva of Mottled Tortoise Beetle (Coptocycla guttata 

 Oliv.); 6, pupa of same; c, adult of same; d, adult Black-legged Tortoise Beetle (Cas- 

 sida nigripes Oliv.); e, adult Two-striped Tortoise Beetle (Cassida bivittata Say). 



, which attack the sweet-potato. There are hardly any 

 other insects which infest this plant, but these beetles are often 

 sufficient in number to do great injury. 



The larvae of all resemble each other in being short, broad, and 

 flattened ; in having six short, thick, fleshy legs, besides a mova- 

 ble, forked tail ; and in having the margin of the body provided 

 with spines. 



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