108 



INJURIOUS INSECTS 



THE PALE-THIGHED TORTOISE -BEETLE. 

 (Cassida pallida, Herbst.) 



This species can scarcely be distinguished from the pre- 

 ceding. It is of a somewhat broader, rounder form, and 

 differs in lacking the black spots on the wing-coverts, and 

 in having the thighs entirely pale yellow, while in auricli- 

 alcea they are black at the base. It likewise feeds upon 

 the Sweet-potato, and its larva differs only from that of 

 the former, in its spines being brighter and lighter col- 

 ored, and in having a dull orange head, and a halo of the 

 same color on the anterior portion of the body. 



THE MOTTLED TORTOISE-BEETLE. 

 (Cassida guttata, Oliv.) 



This species (fig. 74), which is the next most com- 

 mon of those found on the Sweet-potato in the latitude 



Fig. 74. MOTTLED 

 TORTOISE-BEETLE. 



Fig. 75. MOTTLED TORTOISE- 

 BEETLE, a, Larva ; fc, Pupa. 



of St. Louis, is at once distinguished from all the others 

 here described by being usually black, with the shoulders 

 black to the extreme edge of the transparent wing-cov- 

 erts. It is a very variable species, and is frequently more 

 or less speckled or mottled with gold, while more rarely 

 it has a uniform golden appearance. 



The larva, which is represented enlarged and with the 

 dung removed at figure 75, a, is of a uniform green color, 



