WHEAT 95 



GRAIN WEEVILS 



There are several species of grain weevils which 

 attack and often severely damage stored wheat. 

 The two most common in the United States are 

 the granary weevil, the adult insect of which is 

 a small snouted beetle, and the grain moth or 

 angoumois. The larvae of these insects and also 

 the beetle itself attack the wheat kernels, devour- 

 ing the mealy part. They develop and multiply 

 very rapidly. The remedy is fumigation with 

 bisulphide of carbon, one pound to one ton of grain 

 or to 1,000 cubic feet of empty space. Hydro- 

 cyanic acid gas is used for fumigating mills and 

 large grain elevators. Naphthaline is the most 

 effective preventive. 



FUNGOUS DISEASES RUST AND SMUT 



Among plant diseases, rust and smut are per- 

 haps the most destructive. There is no remedy 

 for rust other than the breeding of rust-resistant 

 varieties of wheat, and so far no fully rust- 

 resistant varieties have been produced, although 

 certain varieties growing side by side in a field 

 often show a different susceptibility to the attacks 

 of rust. This may be due, however, to different 

 periods of maturing and to weather conditions 

 as much as to the variety. 



It is estimated that the damage by stinking smut 

 in many seasons amounts to 10% of the total wheat 

 crop of the United States, while certain fields 

 may show a much larger percentage of damage. 

 This disease may be almost wholly prevented. In 



