Packakd.] 



INSECTS OF THE PIELD. 



209 



having the third and fourth stripe from the outside united, 

 \Yliere they are distinct in the potato beetle, and the legs 

 entirely pale yellow, with a dark spot on the thighs. The 

 head of the larva, or grub, is paler than in that of the po- 

 tato beetle. 



A large number of parasitic and external insect-enemies 

 prey upon the potato beetle, and were it not for these friends 



Fig. 155. 



Parasite of Potato Beetle. 



of the farmer, he might well despair. The only insect as yet 



known to live parasitically on the potato beetle is the Lydella 



(Fig. 155, enlarged), described by Mr. Riley under the name 



Fig. 15G. Fig. 157. Fig. 158. Fio. 159. 





S-banded 

 Lady Bird. 9-spottcd Lady Bird. Ilippodamia. Chilocorus. 



of Lydella dorypJiorce. He remarks that "this fly destroyed 

 fully ten per cent, of the second brood and fifty per cent, of 

 the third brood of potato beetles that were in my garden." 



Of the external enemies the lady birds are among the 

 most efficient. (Fig. 156, Coccinella trifasciata; Fig. 157, 

 Coccinella 0-notata, all slightly enlarged ; Fig. 158, Hippo- 

 u 17 



