GEOGEAPHIC STUDY OF STATISTICS. 



21 



with 37.9 per cent, Oklahoma comes next with 30.8 per cent, Arkan- 

 sas with 25.65 per cent, Louisiana with 12.5 per cent, and Mssissippi 

 with 11.7 per cent. Thus it may be seen that the dry, prairie States 

 of Texas and Oklahoma lead in the climatic and predatory control 

 of the weevil and also in the total amount of control, and that the 

 climatic control in each of these States is greater than the total insect 

 control. This latter fact is also true of Arkansas. In Louisiana 

 and Mississippi, States which are naturally more humid, the climate 

 has less influence and the greater proportion of the control is by the 

 insect enemies. 



In hanging squares the conditions are entirely reversed. It is 

 noticeable that Oldahoma leads in parasitism with an average of 31.74 

 per cent, Texas averages 26.6 per cent, Arkansas 24.16 per cent, Mis- 

 sissipi 21.2 per cent, and Louisiana 12.07 per cent. In predator}^ 

 control Louisiana leads with 12.9 per cent, Texas comes next with 10.9 



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Fig. 2.— Diagram illustrating the average climatic and insect control of the immature boll weevils 

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



per cent, Mississippi with 6.98 per cent, and Arkansas with 2.53 per 

 cent. We have no record of predatory control in Oklahoma. In all 

 five States insect control in hanging squares is greater than climatic 

 control. With regard to climatic control Arkansas leads with 26.69 

 per cent, Texas has 16.8 per cent, Louisiana 15.89 per cent, Oklahoma 

 9.53 per cent, and Mississippi 8.12 per cent. These statistics are 

 graphically shown in figures 2 and 3 . 



A brief comparison of the condition in hanging and fallen squares will 

 show that the States of Texas and Oklahoma have a higher average 

 percentage of control from all factors in fallen squares than in the 

 hanging squares ; the States of Louisiana and Arkansas have a higher 

 average percentage of control from all factors in hanging squares than 

 in fallen squares, and in the State of Mississippi the difference is very 

 slight, although in favor of the fallen squares. This illustrates the 



