INFLUENCE OF SHORT DROUGHT IN SAME SEASON. 



13 



Table I. 



■Temporary control of weevil by drought in May and June, Victoria, Tex., 



1906. 





Temperature. Precipitation. 





Month. 



Abso- 

 lute 

 maxi- 

 mum. 



Month- 

 ly mean 

 maxi- 

 mum. 



Month- 

 ly mean 

 aver- 

 age. 



-»-> „ - Num- 



normal - ; S ys y 



Total 

 rain- 

 fall. 



Depar- 

 ture from 

 normal. 



Weevil and crop conditions. 



1906. 

 April . . 



May. . . 



June... 



July... 



°F. 



87 



96 

 103 



97 



°F. 

 79 



86 

 94.3 



91.2 



°F. 

 70.3 



76.4 

 83.7 



82.9 



°F. 

 -2.4 



-1.6 



+ 1.5 



-1.3 



6 

 2 



2 

 12 



Inches. 

 2.88 



.63 



.68 



4.93 



Inches. 

 +0.22 



-3.29 

 -3. 03 



+ 1.73 



Cotton planted early in month. 

 Stand uneven. 



Cotton began squaring about 

 May 20. Weevils coming 

 from hibernation in large 

 numbers. No blooms, as all 

 squares are destroyed as 

 formed. 



Weevils still coming from hi- 

 bernation. No blooms un- 

 til very last of month. First 

 generation weevils nearly all 

 destroyed while immature. 

 Number of weevils in field 

 greatly decreased by June 

 30. Blooms and bolls then 

 forming abundantly. 



Weevils so checked by June 

 conditions that before they 

 could multiply again a good 

 crop was set and a yield of 

 about one-half bale was 

 gathered in September and 

 October. 



It should be noted that in this field a considerable portion of the 

 ground was exposed to sunshine through the unevenness of the stand. 

 The rainfall during April was sufficient to give the plants a good 

 start, and a fair growth was made through the month of May. April 

 and May were somewhat cooler than is usual for those months. The 

 weevils which had passed through hibernation in the vicinity of the 

 field were so abundant early in the season that squares became 

 infested as rapidly as they were formed. Squares began to form 

 before May 1, but no blooms appeared, and conditions seemed to 

 point to the inevitable failure of the crop until after the extreme heat 

 and drought of June. During June the maximum temperature 

 recorded was below 90° upon only one day, when it was 88° F. On 

 three days the maximum temperature recorded was above 100° F. 

 The mean maximum temperature for the month, 94.3°, is therefore 

 exceptionally high. During the seventy-four days between April 

 20 and July 3 rains fell upon only four occasions and the total precipi- 

 tation was less than 1J inches. This extreme heat and drought 

 produced a very marked change in the weevil conditions found in 

 this field. Through the gradual dying off of hibernated adult weevils 

 and the long-continued destruction of their progeny, the number of 

 weevils to be found in the field was very greatly reduced. Following 

 the heavy and well distributed rains occurring in July, the plants 

 quickly put out large numbers of squares, and before the weevils 



