INSECTS INJURIOUS TO BEANS AND PEAS 281 



Fumigation. This is undoubtedly the best means of destroy- 

 ing the weevils, and is now coming into general use. Dr. Fletcher, 

 who has made the most thorough studies of practical methods for 

 controlling this pest, states: "Fumigation with bisulfide of car- 

 bon is a sure remedy. When properly done, either in specially 

 constructed buildings known as ' bug-houses ' or in any tight bin, 

 every weevil is surely killed if the seed containing them is fumi- 

 gated for forty-eight hours with this chemical, using 1 pound by 

 weight to every 100 bushels of seed, or, in smaller quantities, 1 

 ounce to every 100 pounds. For the treatment of small quantities 

 of seed, particularly by farmers, I have found that an ordinary 

 coal-oil barrel is very convenient. This will hold about 5 bushels, 

 or 300 pounds of seed, which may be treated with 3 ounces of bisul- 

 fide of carbon. Care must be taken to close up the top tightly. 

 This is best done with a cap made specially for the purpose, but 

 fine sacks laid smoothly on the top, over which boards are placed 

 with a weight on them, will answer. Fumigation with bisulfide 

 of carbon is, I believe, the remedy most to be relied upon in this 

 campaign. It is perfectly effective, is now regularly used by the 

 large seed merchants, and in future will be much more generally 

 used." 



The Common Bean-weevil * 



Throughout the United States the common Bean-weevil is the 



O n. C 



FIG. 240. The common bean-weevil (Bruchus obtedus Say): a, beetle; 6, 

 larva; c, pupa all greatly enlarged. (After Chittenden, U. S. Dept. 

 Agr.) 



principal enemy of the bean. The small, white, footless grubs 

 feed within the beans, both in the field and in storage, and trans- 

 * Bruchus obtedus Say. Family Bruchidae. 



