240 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 1 



the preceding season at Keachie, La., and Dallas, Texas, among 35,- 

 900 Aveevils, the average survival was only 2.18 per cent. The emer- 

 gence movement began on IMarch 22 and continued until June 28, 

 1906. These are unquestionably closer to the normal facts regarding 

 emergence than are the figures shown in 1907. We have thus in two 

 seasons a range in percentage of survival of from 2 to 11 per cent and 

 in emergence from February 15 to the end of June. These facts em- 

 phasize very strongly the importance of reducing the number of 

 weevils entering hibernation. 



In order to make the following facts represent general conditions 

 and avoid the possibility of being misled in our conclusions by the va- 

 riations which might reasonabh^ occur in a single experiment, we 

 shall present the data in groups of experiments and base our conclu- 

 sions upon the average results shown by the totals and average per- 

 centages for each group. The chronological significance of the data 

 may be most clearly sliown l)y groui)iiig the records for those local- 

 ities at which experiments were started upon the same or approximate 

 dates. The shelter and food conditions represented in each group are 

 therefore fairly averaged and the time at which the experiments were 

 started becomes the most significant factor in each group. The de- 

 sired comparisons can be most briefly shown by tabular arrangement. 



In Table IV it may be seen that averaging all localities at which 

 weevils were started upon approximately the same date, there is a 

 most striking increase in successful survival from the middle of Oc- 

 tober to the middle of November. In the interval of eleven days 

 from October 14 to 25 the percentage of survival practically doubled. 

 During the next ten days the percentage again doubled and a corre- 

 sponding increase is observable between November 5 and 14. After 

 that time hibernation might have been successful for practically the 

 maximum possible proportion of weevils. The first freeze occurred 

 on November 18. The facts shown may appear more emphatic if 

 stated in another way. Under otherwise similar average conditions, 

 the chances for survival for weevils in Texas in 1907 were : On Oc- 

 tober 15. one ; October 25. two ; November 5, four ; November 15, six. 

 These facts make it plainly evident that from October 15 to Novem- 

 ber 15 constitutes the strategic period for attack upcm the boll wee- 

 vil. The data and conclusions are here given that they may be studied 

 carefully by those who are interested to do so. 



Conclusions Drawn from Data Presented 



Application of Conclusions. — The method of attack which has 

 proven most effective consists of the successive steps constituting the 



