144 



The Sweet Potato 



FiGTJEE 15. — The smaller sweet potato saw-fly {Schisiocerus 

 eierms) : a, h, larva; c, d, segments of larva showing spines; 

 e, eggs deposited under leaf; /, male saw-fly; g, antenna of female 

 saw-fly. All much enlarged; c, d, greatly enlarged. 



near OceaB Springs, Mississippi. Two species have 

 been identified on sweet potatoes, Schizocerus ebenus 

 and Schizocerus privabus. These insects usually com- 

 mit their -depredations in the middle of the summer, 

 probably the first appearance being in July. The eggs 

 are deposited on the leaves and the larvsa hatching from 

 them eat the leaves to a honey-comb, the damage last- 

 ing from two to four weeks. These larvae are pale 

 green in color with rows of small dots or tubercles run- 

 ning longitudinally along the body. When seen 

 through the microscope, small fine hairs are readily 

 noticed. When saw-flies become serious in a field, an 



