22 



INSECT ENEMIES OF THE BOLL WEEVIL. 



difficulty of giving any single recommendation for the control of the 

 boll weevil which would apply to all regions. This point will be 

 brought out more fully in other sections of this bulletin. 



5. A STUDY OE THE SHARE OF INSECT CONTROL IN THE MORTALITY OF 

 IMMATURE BOLL WEEVILS. 



The condensed tables which have been presented are likely to give 

 the impression that the parasite control of the weeyh is on an average 

 very low, but it must be remembered that the examinations have 

 been made in all parts of the infested region whether the weevil has 

 been present 17 years or only a few months, and whether the weevil 

 damage amounts to less than 1 per cent of the crop or to almost 100 





PER CENT 

 /O 20y 30 40 SO 60 





0.7, 

 I //. 82 





2S.6S 





8.18 



37.9 



M^=-pk£a^To/?s 



1 \ = a.//WATE 



ARKANSAS 

 LOUJSJAAJA 



te:xas%^ 



OKLAHOMA 

 M/SSfSS/PPI 



immm 



VA 





\3 



r 



/8J 



J2.S 





w^^m. 



'm^/m 



\ 



ZJ33./e 



3.9 



20.6 







w^m^ 



^^^^$^$$$^ 



y/^A 









_\62.^ 





22 J 6 







30.8 





Z67 



iBt^^^^^, 



W/////////A 



'<^y^y^ 







IS 



/^.2. 



7/ 



63 



//.7 



7.60 





wmsm 





mm 



\S 









Fig. 3.' 



-Diagram illustrating the average climatic and insect control of the immature boll "weevils 

 during 1906, 1907, 1908, and 1909, in fallen squares. (Original.) 



per cent. This great difference in the sources of the material exam- 

 ined has necessarily lowered the average mortality to its minimum. 

 The following records show some of the cases of very high mortality 

 due to parasites: 



Highest records of parasitism of the boll weeviL 

 IN FALLEN SQUARES. 



Locality. 



Date. 



Number 

 of stages. 



Percent- 

 age of 



parasit- 

 ism. 



Robson, La , 



Corpus Christi, Tex 



Natchez, Miss 



Dallas, Tex 



GoUad, Tex 



Natchez, Miss 



Cuero, Tex 



Natchez, Miss 



Shreveport, La 



Victoria, Tex 



Roosevelt, Tex 



Arlington, Tex 



Brownsville, Tex. . . 



Denison, Tex 



Atoka, Okla 



Nov. 5, 1907.. 

 June 20, 1907. 

 Oct. 23, 1908., 

 Aug, 12, 1908. 

 July 28, 1908. 

 Oct. 16, 1908., 

 Aug. 12, 1907. 

 July, 1909.... 

 Oct. 29, 1908., 

 Jime 19,1908. 

 Sept. 24, 1906, 

 July 17, 1908. 

 Sept. 5, 1906.. 

 July, 1909.... 

 Sept. 2, 1908.. 



53 



92 

 157 



18 

 114 

 230 

 105 

 200 

 624 

 513 



69 



382 



1,147 



494 



100 



77.86 

 36.95 



28.6 

 27.78 

 26.63 

 2L7 

 19.04 

 18.5 

 15.8 

 14.5 

 14.4 

 13.35 

 12.4 

 8.5 

 8.0 



