172 



THE MONTHLY BULLETIN. 



THE ANGOUMOIS GRAIN MOTH. 



Sitotroga ccrealclln OVw. (Family Gelechiidae). 



( Fig. 157.) / 



General Appearance. — The adult females are light-yellowish, irides- 

 cent brown with few darker markings on the fore wings. They average 

 about one inch in length, including folded wings. The very small eggs 

 are oval elongate and slightly i)inkish in color. The larvre are scarcely 

 over one fourth of an inch long but more often small enough to com- 

 fortably occupy the inside of a wheat or barley kernel. They are 

 robust and white. The pupa? are pale j^ellowish-brown. 



Fig. 157. — The angoumois s'lfiin moth (Sitotroga cerealella Oliv. ), showing larvse, 

 pupae, adults and tlie worlv on Ivcrnels of popcorn. (Original.) 



Life History. — In grains, the eggs are deposited on the outsides of 

 or between the kernels in the head or on the cob. They are laid in the 

 field in late summer and fall, but in storehouses egg-laying maj^ con- 

 tinue throughout the year. As soon as the young hatch they bore a very 

 minute hole and work their way into the interior of the kernel. In 

 wheat and barle.y only one individual occupies the interior, w^hile in 

 corn there may be several or many. The larval and pupal stages are 

 passed within the kernel, which is completely destroyed. The adult in- 

 sect emerges through a small circular hole cut in the thin wall and 

 escapes to mate, soon to start other broods. The life cycle occupies 

 about forty days, there being many overlapping broods a year. In 



