54 JOURNAL OP ECONOMIC ENTOMOLOGY [Vol. 3 



was made of sample lots of corn taken from near the top, at about 

 the middle and at between one and two feet from the bottom of each 

 bin. Corn in these cribs averaged between seven and eight feet in 

 depth and was all stored with the shuck on. The examination showed 

 that in the large crib an average of about 7 per cent of Calaudra sur- 

 vived. In some of the cribs receiving the weaker treatment, there was 

 an average of between 25 and 30 per cent of Calandra stages alive. 

 The corn was leveled off in the cribs and covered with a special water- 

 proof, and apparently gas-tight, tarpaulin in each crib before the 

 di-suliid was applied. A recording thermograph and hygrograph was 

 placed near the middle of one mass of corn to give those records for 

 a week following the application. When all preparations had been 

 made, "Fuma" carbon di-sulfid was applied in various cribs at the 

 rates of 3, 5, 6 and 8 pounds per 1,000 cubic feet. The liquid was 

 poured directly on to the corn, the tarpaulins spread over it as quickly 

 as possible, and the doors, which had been previously padded, were 

 closed and nailed tightly. To insure still further tightness around the 

 doors, papers were pasted over the entire door and frame to each 

 crib. The only possible escape for the gas in these treatments would 

 seem to have been around the edges of the room between the tarpaulin 

 and the wall and upward and outward along the eaves. Subsequent 

 examinations showed that the temperature at the time of beginning the 

 experiment was between 57 and 58 degrees F., with the humidity aver- 

 aging about 60 per cent. During the week after the treatment was 

 made, both temperature and humidity arose steadily and gradually to 

 a maximum of 63 degrees F., and 77 per cent humidity for the middle 

 portion of this mass of corn. Under these conditions, a l)rief consid- 

 eration of the results may be of interest. The examinations entailed 

 a large amount of routine work, which could not be avoided on account 

 of the necessity for determining the effect upon immature stages as 

 well as upon adult insects. In the crib where but 7 per cent of Calan- 

 dra stages were alive at the middle of October, there was about 32 per 

 cent of living stages by the first of December in spite of the applica- 

 tion of 8 pounds per 1,000 cubic feet. Similarly, in the other cribs, 

 the percentage of living stages had largely increased before the exam- 

 inations were completed. As a whole, it must be admitted that the 

 treatments yielded very disappointing results, and in comparison 

 Vv'ith the fair degree of effectiveness of the treatment made at the mid- 

 dle of September, the principal varying factor which may offer a basis 

 of explanation again seems to be the difference in temperature prevail- 

 ing at the time the treatments were applied (57 vs. 80 degrees F.). 

 In another place where corn was stored, in one corner of a barn, the 



