18 



HIBERNATION OF THE COTTON BOLL WEEVIL. 



Table II. 



■Counts to determim number of weevils per acrt at time of entrance into 

 hibernation, in thret localities in Texas. 



Date. 



Locality. 



Plants 



per acre. 



Plants 



exam- 

 ined. 



Weevils 



found. 



Weevils 



per acre. 



Rem 



1904. 



• 



Terrell 



10,890 

 10,890 



10,890 



100 

 100 



50 



267 



61 



5 



7 



29,076 



762 

 1,742 





Nov. 9 



do 



.do 



Defoliat 





do 



Averages and totals. 



Calvert 



Do. 





HI.VKI 



320 



340 



11,570 



• four fields examined 



• rrell. 



Nov. 16 



7,260 



: . -•• ■' i 

 7,260 

 7. 260 



7,260 

 7,260 



30 

 40 

 30 

 30 

 30 

 30 

 50 



4 



4 

 9 



39 

 4 



21 



968 



2,178 

 900 





Do 



do 



Do. 



Do 



do 





Nov 17 



do 





Do 



do... 





Do 



....do 





Nov. is 



do 



Averages and totals. 



Defoliated. 





7,260 



240 



160 



4,840 



• seven fields exam- 

 ined at Calvert. 



1905. 

 Nov. 14 



6,200 

 6,200 

 6,080 

 6,200 

 6,200 

 7,000 



46 

 66 



5 



10 

 10 



2 



47 

 22 

 48 

 46 

 LI 

 25 



6,355 



2,073 



58,368 



1,000 

 50,000 





Do.... 

 Do 



do 



...do... 



Do. 

 Many squares. 

 Do. 



Do... 



...do 



Do 



do . . . 





Nov. 27 



do 



Averages and totals. 



Estimate reduced. 





6,313 



139 



204 



9,266 



Average six fields examined 

 at Wharton. 



In connection with the work done at Dallas during the fall of 1906 

 repeated estimates of the number of weevils per acre to be found 

 upon the stalks were made in the same field beginning October 12, 

 1906, and ending January 21 , 1907. These figures are presented in 

 Table III. The number of plants per acre in this field was S.300. 



Table III. — Number of weevils per acre upon stalks at different dates at Dallas, 



Date. 



Plants 

 exam- 

 ined. 



Living 

 weevils 

 found. 



Living 



weevils 

 per acre. 



1906. 

 Oct. 12 



110 



M 

 60 

 35 

 35 

 36 

 35 



35 



122 

 190 

 106 

 29 

 27 

 10 

 5 



3 



9,205 



is. 771 



14,663 



• 



6,403 



1,186 



711 



Oct. 31 to Nov. 3 



Nov. 10 



Nov. 20... 



Nov. 22 



Dec. 1... 



Dec. 18 



1907. 

 Jan. 21. . 





The table given above shows a number of points which are of 

 exceptional interest. About November 1 it may be seen that the 

 number of weevils present was more than double the number of plants. 

 After that time there was found to be a steady decrease in the number 

 of weevils present upon the stalks. The most abrupt change was 

 to be found between November 10 and 20, when more than one-half 



