THE WHEAT CKOP. 



81 



the contents of the grain, until the husk alone is left, 

 which lasts them until they have arrived at maturity and 



1. Grain of wheat, showing the punctured hole ; and 5, the exit of the per- 

 fect weevil. 2. Pupa ; 3, magnified. 4. Grain of Indian corn, with weevil 

 inside. 6 and 7. Corn-weevil, natural size and magnified. 8 and 9. Rice- 

 weevil (C. oryzce), natural size and magnified. 



changed to pupa. In about six to eight weeks from the 

 time of impregnation the perfect weevil is produced, 

 which eats its way through the husk, and is then ready 

 to propagate its species. In five months a pair of weevils 

 have been known to produce 6045 individuals, each of 

 which required for its cradle a grain of the farmer's crop. 

 Owing to the workmanlike manner in which the female 

 deposits her eggs, it is very difficult to detect their presence 

 in the grain, which is generally not discovered until the 

 perfect animals are seen walking over the heap, when the 

 empty husks* are readily picked out. Their specific gravity 

 being much lighter than sound grains, they may always be 

 discovered if placed in a basin of water the sound grains 

 sinking, and these floating on the surface. They are very 

 soon destroyed by a low temperature ; granaries, therefore, 

 in which they have been noticed, should be opened, and 

 exposed as much as possible to the winter frosts. Where 

 malt, of which they are very fond, is infested by them, 



