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BULLETIN 1393, TJ. S. DEPARTMENT OF AGEICULTURE 



"weevil. The adults were not only causing a general infestation of the 



frain, but were opening the cartons to the attack of other grain pests 

 y boring small holes in their efforts to escape, similar to those made 

 in piU boxes and shown in Figure 6. The entire shipment was con- 

 demned. 



Injury by the larvae consists in the destruction, by feeding, of a 

 larger or smaller part of the kernel, and in the fouling of the seed by 

 their excrement. The development of one granary weevil larva will 

 reduce the weight of a wheat kernel over 50 per cent and the adult 

 before leaving the kernel may destroy even more. The destruction 

 caused in all grains depends largely upon the abundance of the larvEe. 



Fig. 3. — Wheat kernels damaged not only by development of larvae but by continued feeding of 

 adult beetles of the granary weevil. These kernels are reduced to mere skeletons and can be 

 crushed flat as paper by the least pressure 



Horses and other stock have been reported at times injured by being 

 fed weeviled grain or other grain products filled with the feces and 

 other debris left in the grains when these are infested. Recent 

 investigation by Riley (57) and Defiel (17) show that the granary 

 weevil has no poisonous qualities. The writers have seen very badly 

 weeviled grain fed to animals without bad results and have yet to estab- 

 lish a clear instance in which injury to animals was caused by weevils. 



Badly infested seeds, particularly wheat (fig. 3) are rendered 

 worthless for seeding. 



The destructive possibilities of the granary weevil were clearly 

 shown during the World War when immense quantities of wheat were 

 stored in Australia, a considerable quantity of it, owing to a lack of 

 shipping, being held in storage for several years. This wheat became 



