CONTROL OP BOLL WEEVIL IN MISSISSIPPI DELTA. 



WEEVILS COLLECTED. 



Throughout the experimental period a record was kept of the 

 number of weevils gathered from each row of each plat at each pick- 

 ing. These records are only of incidental interest, as the extreme 

 smallness of the plats, of course, allowed more or less of an interplat 

 movement of weevils every day, and the records secured bear no 

 relation to the conditions which would exist if larger tracts were 

 picked at the different time intervals. However, the row and plat 

 totals and plat averages for the season are of some interest and are 

 given in Table 1. 



Table 1. — Total number of weevils collected, by rows and plats, Eureka plantation, 



Talluluh, La., 1916. 



Plat No. 



Total 

 number 



of 

 pickings. 



Row No. 

 1. 



Row No. 

 2. 



Row No. 

 3. 



Row No. 



4. 



Plat 

 total. 



Average 



per 

 picking 

 for plat. 



1 



54 

 45 

 36 



27 

 18 

 9 



275 

 229 

 169 

 127 

 92 

 81 



257 



203 

 167 

 174 

 114 

 60 



130 

 184 

 243 

 100 

 108 

 84 



210 

 .176 

 176 

 136 

 110 

 62 



872 

 792 

 755 

 537 

 424 

 287 



16.1 



2 



17.5 



3 



20.9 



4 



19.8 



5 



23.5 



6 



31.8 







From this table it is seen that, generally speaking, the weevils per 

 picking increased about in proportion to the increase in the time 

 interval between pickings. However, the average number of weevils 

 per picking in plat 6 was only twice that of plat 1, whereas plat 1 

 was picked six times as often as plat 6. The fact that there was an 

 increase in the number of weevils secured per picking with the 

 decrease hi the number of pickings shows that the weevil movement 

 within even these small plats was at least not sufficient to equalize 

 the distribution completely throughout the plats between the pick- 

 ings. This point is of principal interest in connection with the con- 

 sideration of the important question of the extent and effect of the 

 interplat movement of weevils in the larger field tests, which will be 

 discussed later in the present report. 



FORMS COLLECTED IN BAGS. 



In the same way that the weevil collections were recorded the 

 forms gathered in the sacks from each row at each picking were 

 noted. These forms were examined each time and divided into 

 squares and bolls; then these were re divided into those uninjured 

 (termed "clean"); those weevil punctured, and those showing other 

 injury, such as rot, worm injury, etc. The plat totals secured during 

 the different pickings are shown in Table 2, and are rearranged in 

 Table 3 to show the averages per picking for each plat. 



