4 INDIAN-MEAL MOTH AND WEEVIL-CUT PEANUTS. 



used very successful!}", both in the control of the Indian-meal moth 

 and in that of the related Mediterranean flour moth. Both Prof. 

 G. A. Dean, of the Kansas Agricultural Experiment Station, and the 

 author have used this method in the control of the flour moth, and it 

 was used quite successfully by the latter in a peanut mill in Virginia. 

 It is. of course, only aj^plicable to mills heated by steam. In the 

 proper application of this method the mill should be thoroughly 

 piped and furnished with suitable radiators. Sufficient radiator sur- 

 face should be supplied to obtain a temperature of 120° to 125° F. 

 A few courses of l:J-inch pipe placed along the side walls should 

 easily bring about the desired results. If a warm day in the summer 

 is selected and the steam is employed at a pressure of 75 to 100 

 pounds, only a small amount of radiator surface is needed. To 

 permit the most effective penetration of the heat, the bags of nuts 

 should be piled only a few feet deep, as experience has shown that 

 some time is required for the peanuts within the piles to be raised to 

 a uniform high temperature. The building should be closed tightly 

 and the temperature raised to 120° F., remaining at this point for at 

 least G hours. A longer time is advisable, as the penetration is 

 thereby increased. Bags of shelled stock are with difficulty heated to 

 the center without a long exposure, and although the larvse work 

 near the outside of the bags the}^ may crawl to the center to escape 

 the great heat, which tends to make them much more active. 



The temperature should not be raised above 125° F. in the case of 

 peanuts, as experiments have shown that a slight degree of blanching, 

 or slipping of the " sldn," takes place in shelled Spanish nuts exposed 

 to such a heat. Virginia peanuts, being much less oily, are not 

 affected, while no injury whatever takes place in the case of unshelled 

 nuts. Germination is likewise unaffected, peanuts exposed 6 hours 

 to a temperature of 140° germinating better and more quickly than 

 those unheated. A temperature of 116° is fatal to insect life in a 

 short time, larvse, pupae, and adults of the Indian-meal moth dying 

 in less than one-half hour, when exposed. 



Fumigation. — In mills and storehouses where the heat method is 

 inapplicable, it may be necessary to fumigate with hydrocyanic-acid 

 gas. On account of the extremely poisonous nature of this gas care 

 is necessary in its use., and, where careless or ignorant helj) is em- 

 ployed, some danger might accrue through improper or careless 

 handling. Before the gas is applied the building should be tightly 

 closed; afterwards jars containing the requisite amount of diluted 

 sulphuric acid should be placed therein, and the paper bags contain- 

 ing the cyanid of potassium dropped into these jars, thus liberating 

 the gas in the room. This gas is used extensively as a remedy for 

 flour-mill and household insects, and where intelligently handled 



