SWEET POTATO INSECTS 



237 



The hlack'legged tortoise beetle, Cassida nigripes Olivier 



This beetle (Fig. 144) is a little over ^ inch in length. When 

 at rest in the sunshine, it is of a beautiful golden tint but loses 

 its brilliancy when disturbed and after death fades to a yel- 

 lowish brown. Each wing-cover is marked with three black 

 spots arranged in a triangle. The legs and 

 the tip of the antennae are black. The eggs 

 are laid in rows of three to twelve on the 

 stems of the plant. The larvae are bright 

 straw-yellow with a curved black mark on 

 each side of the prothorax. The spines along 

 the side of the body are tipped with black. 

 The anal fork is carried close to the back and 

 the excrement is arranged in a characteristic ^ig. 144. — The black- 

 manner with long shreds extending out side- legged tortoise beetle 



• • ( X 5) 



wise. The pupa is dark brown with the 



lateral spines transparent white. The larvae reach maturity in 



about two weeks and the pupal period is nearly as long. 



The golden tortoise beetle, Coptocycla bicolor Fabricius 



When basking in the sunshine, this beetle has been likened 

 to a drop of molten gold ; the coloration becomes duller, how- 

 ever, when the insect is disturbed or in 

 cloudy weather and after death fades to a 

 light reddish brown. The scientific name, 

 bicolor, was apparently given because of 

 the contrast between the golden central 

 part of the body and the thin semi-trans- 

 parent margin. The beetle (Fig. 145) is 

 little over ^ inch in length. The 

 eggs are glued singly to the underside of 

 the leaf. The eg^ is about -^ inch in length, dirty white in 

 color, rounded below, ridged on the sides above and is usually 

 armed at one end with three sharp diverging spines. The 



Fig. 145. — The 

 golden tortoise a 

 beetle (X 5), 



