50 DISEASES OF CROPS. 



the largest in Europe. It often measures from five to six 

 inches across the extended wings. The skin of the moth 

 is variegated with black, dark-brown and yellow ; and 

 bears upon the back of the thorax a deep orange mark, 

 presenting no inconsiderable resemblance to the front of 

 a human skull. A. atropos " utters '' a sharp squeaking 

 sound. 



The larvae (caterpillars) of this moth are also very large, 

 often measuring from four to five inches long, and as thick 

 as a man's finger. They feed upon the leaves of the potato 

 plant duriug the evenings, but, according to Miss Ormerod, 



Fig. 21.— Potato Fkog Flt {Eiipteryx solani). 



A. Frog fly (enlarged). 



B. Eggs (imt. size and enlai^ed). 



" seldom cause any serious amount of damage." They are 

 provided with feet and strong jaws. The skin of the 

 caterpillar is of a pale yellow colour, with seven oblique 

 violet stripes along the abdominal segments. The larvse 

 change their skins, and are transformed into the pupal 

 stage, at least one foot deep in the ground. For this 

 reason they have been termed subterranean pupse, and are 

 often turned up La digging potato grounds. The pupa is 

 chestnut coloured. The perfect insect makes its appear- 

 ance from August to October. 



Prevention and Cure.—{1) Handpicking. (2) Liming 

 the land destroys the pupse. 



