Angoumois Grain Moth. 11 
ing in the field. In storage the pest breeds generation after genera- 
tion as long as the food supply lasts. This may be several years in 
what are commonly believed to be “air-tight” containers. In agri- 
cultural districts, especially where the pest is breeding in storage 
in open bins or mows, the moth is driven by instinct to leave the 
warehouse, barn, or crib in varying numbers and fly to the near-by 
fields in search of maturing grains in which to lay eggs for the 
first summer generation in the field. Of course many remain behind 
in the crib to multiply continuously throughout the year. 
INFESTATION OF CORN. 
Corn has an advantage over the smaller grains in that most of the 
kernels are covered during growth by the husk covering. It has 
already been pointed out that destruction by the Angoumois grain 
moth takes place in the larval stage. The parent which flies from 
grain in storage to the field to start the first generation in maturing 
grain can not eat into the shuck covering. Hence corn protected 
by a well-developed, uninjured shuck covering ‘is never affected. 
But where the shuck is either loosely developed at the tip or damaged 
by smut, corn earworm,* or other insects, the moth can easily reach 
the kernels and lay her eggs upon them, thus starting an infestation. 
These relatively few cases of infestation in the field serve as cen- 
ters of infestation from which following generations of moths matur- 
ing in standing corn or corn shocked in the field, or corn that has 
been placed in the crib, will spread in large numbers and bring about 
a general infestation of the entire lot of corn in storage. There is 
practically no infestation of corn in the field except in the more 
southern States. As 
far north as Mary- 
land instances of 
field infestation are 
very rare and there 
is little danger of 
infestation where 
corn is stored in 
ordinary slatted 
cribs until the com- 
Ln Se: of: Swi ri 
weather of the fol- 
lowing summer. But 
in the Gulf Coast 
States, especially 
Fic. 9.—Kernels of wheat showing the small round when the corn is 
emergence holes that prove that an Angoumois grain o cal 
; 5 - rowing on oor 
moth has developed in the seed, thus reducing its weight = = Boe! 
somewhat over 50 per cent. land, where shuck 
8 Chloridea obsoleta Fab. 
