a) ee 
ity in bolls left on plants was lowest, standing cotton stalks should 
be considered a dangerous factor in increasing the winter survival of the 
pink bollworm in the Laguna district." 
Diluted calcium arsenate gives good control of boll weevil .——-Exper— 
iments conducted last year to reduce the quantity of calcium arsenate 
needed for boll weevil control in the coastal plains sections where ar— 
senical poisoning of the soil occurs, are being repeated this year at 
Florence, S. C. F. F. Bondy reports that he is obtaining very good wee— 
vil control, based on square infestation and blooms produced, by mixing 
hydrated lime with calcium arsenate. One part of calcium arsenate with 
1 and 2 parts of lime are giving almost as good control as straight cal— 
cium arsenate, and al to 3 mixture is giving fair control. Early "mop= 
pings" of 1-1~1 molasses-—calcium arsenate—water mixture alone failed to 
control the weevils, although 3 early applications of the mixture fol— 
lowed by calcium arsenate dusting was slightly better than dusting alone. 
M. T. Young, Tallulah, La., reports that no marked difference has yet been 
shown in the square infestation records of the plats where calcium ar-— 
senate, 1 part to 1 part lime, and 1 part to 2 parts lime, is being used. 
Natural control of the boll weevil.--The effects of heat, para— 
Sites, predators, and other means of natural control on the boll weevil 
are shown by data submitted by H. C. Young, Eufaula, Okla. The boll 
weevil infestation was so light throughout June and July that much of 
the older cotton suffered very little damage and set a good crop of 
bolls. During June and the first half of July the weather was very hot 
and dry, the temperature reaching 108.5° F. on July 11, and was over 100° 
F. on 8 of the first 12 days of July. This was followed by 3.48 inches 
of rain and by cooler weather for the rest of the month. In July represen— 
tative samples of weevil-infested squares (fallen and hanging) were col-— 
lected from a number of fields and examined to determine the percentage 
of dead weevil stages and the cause of the mortality. The data obtained 
explain why the weevil infestation increased so slowly during this per- 
iod. During the hot, dry weather of early July more than 90 percent of 
the weevils in the fallen squares were killed, 71 percent being killed 
by heat. With the rains and cooler weather during the latter part of 
the month, the mortality dropped to about 32 percent in the fallen 
Squares, less than 2 percent being attributed to heat. With the moder— 
ation in the weather the increase in mortality by predators, parasites, 
and proliferation was very noticeable, the parasitization increasing from 
5.47 percent to 12 percent. The mortality in hanging squares was never 
aS high aS in the squares on the ground (fallen) and the effects of the 
change in climatic conditions were not so pronounced. The percentage 
of parasitization. in the hanging squares was consistently much higher, 
ranging from 27 percent to 50 percent, and did not vary as much as in the 
fallen squares. Parasites were also abundant in the Lower Rio Grande 
Valley of Texas, but scarce in the Mississippi Delta. T. C. Barber, 
Brownsville, Tex., reports for July 3 to 24 that 31 percent of the weey— 
ils in fallen squares and 27 percent of those in fallen bolls were par~ 

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