SHARE OF INSECT CONTROL IN WEEVIL MORTALITY. 



27 



Following the plan adopted for the 1906 and 1907 records these 

 figures may be weighted for comparison witli tlio earlier records. 



Table XII. — The hypothetical or weighted average mortality of the boll weevil in 1908.^ 



• Given 10,000 weevil stages. 



This table shows a weighted increase of 2.51 per cent for parasites 

 and a weighted decrease of 12.24 per cent for all agencies, due to 

 the falling off in control by both climate and predators. 



1909. — The mortality during 1909 was 41.73 per cent when figured 

 from the total number of stages, the total mortality thus showing 

 a decrease of 2.61 per cent from 1908. The parasitism showed 

 also a decrease amounting to 4.68 per cent. 



Table XIII. — Boll-weevil mortality in I'jO'J. 



