140 The Sweet Potato 



for a bit of mud sticking to a leaf. This bulk borne on 

 the fork has given them the name of peddlers. When 

 fully grown, the larva fastens itself to a leaf, its skin 

 splits along the back, and the pupa is held to the leaf 

 by its fork. About a week or ten days later, the adult 

 beetle emerges, eats for a time and then disappears from 

 the sweet potato patch until the following spring. It 

 doubtless feeds on its wild food plants until cooler 

 weather drives it into hibernation. 



The two-striped sweet potato beetle {Cassida hivittata). 



This species is usually the most common of the tor- 

 toise beetles attacking sweet potatoes. The beetle is 

 pale or yellow-brown, striped with black. The larva is 

 yellowish-white with a longtitudinal band along the 

 back, on either side of which is a much lighter band. 



The hlacTc-legged tortoise beetle (Cassida nigripes). 



This species very closely resembles the golden tor- 

 toise beetle, but is not so brilliant in color, is larger, 

 has black legs and three black stripes on each wing- 

 cover, and is larger and more readily seen than the 

 golden species. The larva is a bright straw-yellow with 

 two black marks just back of the head, and with the 

 body-spines tipped with black. As with the adult, the 

 larva is much larger than that of the golded beetle. 

 This larva causes more injury to the plants, although 

 possibly it is not as common as the striped beetle. The 

 eggs of the other species are laid singly, while those of 

 the black-legged tortoise beetle are more or less bunched, 

 usually placed in rows of about three dozen. As soon 

 as the larvae hatch, all being on one plant or leaf, their 



