Insects Affecting Sweet Potatoes 



141 



injury is very noticeable, certain plants being de- 

 voured and others not injured at all. 



The golden tortoise beetle {Coptocycla bicolor) (Eig. 

 14). 



This is one of the commonest species and is found 

 on morning-glory and bindweed during practically the 

 whole summer. The beetles on first emerging are dull 

 orange with three prominent black dots on each wing- 



FiGUEE 14. — The golden tortoise beetle: a, adult; J, larva; c, 

 faecifork; d, pupa (enlarged). 



cover, but a little later they assume a metallic color, 

 shining like the most brilliant colored tinsel, and the 

 black spots are not so conspicuous. All the tortoise 

 beetles, and particularly this species, have the habit 

 of dropping quickly to the ground and feigning death 

 when the plant is shaken or when they are disturbed. 



The eggs of this beetle differ from those of other 

 species in having three spinal prongs projecting from 

 the posterior margin. The larva is easily distinguished 



