♦ )S WNl'Al. ItK l'oi;'l> OF DEPARTMENT OF AGRICULTURE. 1939 
annual damage for the United States during the last 25 years. The 
severest damage since L932 occurred along the Atlantic seaboard in 
Virginia, North Carolina, South Carolina, Georgia, and Florida. 
but in other sections a hot, dry period during the first half of July 
temporarily checked a high early-season infestation and permitted 
the early-planted cotton to mature before the weevils became suffi- 
ciently abundant to cause great injury, although late-planted cotton 
was seriously damaged. Large areas of cotton in the central and 
in parts of the Cotton Belt were defoliated by the Leaf worm 
during September L938, and this greatly reduced the numbers of 
weevils entering hibernation. At Tallulah, La., only | live boll 
weevils per ton of Spanish moss were found in the fall of 1938 as 
compared with 51 weevils per ton in L937. This was the smallest 
Dumber of weevils per ton of Spanish moss in the fall since tlie 
examinations were begun in L925. In the eastern pari of the bell 
defoliation by leaf worm- was Light, and Large numbers of weevils 
went into hibernation. At Florence, S. C, winter examinations of 
trash from woods adjacent to cottoniields revealed 3,582 weevils per 
acre as compared with 1,476 in 1937. Most of the weevils were found 
in trash within LOO feet of the edge of the wood-. The survival in 
hibernation cages during the winter of p.>:}^-:; ( .) was somewhat Lower 
than during L937-38 and also Lower than the average survival Inl- 
ine last s years. At Florence the survival was 2.54 percent, at 
Tallulah 1.16 percent, and at College Station 2. 56 percent. At 
Florence weevils again emerged from hibernation in nature much 
later than in the cages. Eighty percent of the emergence in the 
cages occurred during May. whereas only lo percent of the total 
number of weevils collected in a trap plot of cotton were taken 
during May and 33 percent after June 15, when squares were present. 
In experiments in boll weevil control in Tallulah. in which over a 
period of years the standard treatment of calcium arsenate dust had 
been used after 10 percent of the squares had become infested, the 
average gains for the year were 188 pounds of seed cotton per acre. 
or 9.6 percent, as compared with an 18-year average of 322 pounds. 
eriments were continued in several localities with mixture 
calcium arsenate and other materials that might control the boll weevil 
with smaller quantities of arsenic and at the same time control the 
cotton flea hopper, leaf worms, and other insects. At Florence, where 
the boll weevils were abundant and ilea hoppers very scarce, plots 
dusted with mixtures of calcium arsenate and Lime I 1 to 1 and 1 to 2) 
made an average gain of 352 pounds of seed cotton per acre; those 
dusted with calcium arsenate and sulfur (1 to 1 and 1 to 2), a gain 
of [84 pounds; and those treated with calcium arsenate undiluted. 
522 pound-. At State ( Jollege, Miss., where the 1><>11 weevil infestat ion 
was moderate and cotton Ilea hoppers and the rapid plant bug scarce, 
the infestation and yield records showed no significant differences be- 
tween the insecticides; in late-planted cotton, where the weevil damage 
heavy, use of the L-to-1 mixture of calcium arsenate and sulfur 
brought about a gain of 666 pound- o\' ^v^A cotton per acre, as com- 
plied with 626 pounds when undiluted calcium arsenate was \\^i\. 
At Tallulah, where the weevil infestation was light and the tarnished 
plant bug and rapid plant bug more abundant than in Mississippi, 
the gain from mixture- of calcium arsenate and sulfur (1 to 1 and I 
