INSECTS INJURIOUS TO MISCELLANEOUS CROPS 385 



Life History. The beetles hibernate over winter and in the 

 spring before the sweet-potato plants are set they feed on their 

 native food-plant, the morning glory. As soon as the plants are 

 set out, the beetles commence to eat large round holes in the 

 leaves, and so riddle them that many often must be replanted. 

 The worst damage, however, is done to the set on which the 

 eggs are laid. Rarely are the new shoots seriously eaten or are 

 eggs laid upon them. The larvae hatch during the first half of 

 June in Maryland, and require slightly over two weeks to become 



FIG. 321. Above The golden tortoise-beetle (Coptocycla bicolor Fab.): a, 6, 

 larvae; c, pupa; d, beetle; egg at right all enlarged. (After Riley.) Below 

 The two-striped sweet-potato beetle (Cassida bivittata Say) : 1, larvae on leaf; 

 2, larva; 3, pupa; 4, beetle all enlarged. (After Riley.) 



full grown. Though the larvae do considerable damage by eating 

 the foliage, it is not nearly as serious as that done by the beetles. 

 The larvae are almost as disagreeable as the adult beetles are 

 attractive, but are nevertheless very interesting creatures. Each 

 of them is provided with a tail-like fork at the end of the body 

 which is almost as long as the body, and in those species in which 

 it is depressed, entirely conceals the insect. Upon this fork is 

 heaped the excrement and cast skins of the larva, and when 

 covered by this "umbrella" it is with great difficulty that the 

 larva is distinguished from a bit of mud or a bird-dropping. 

 The manner in which this fork increases with the size of the 



