RETENTION OR SHEDDING OF INFESTKD FORMS. 



31 



increased the destruction of weevil stages by these factors to about 68 

 per cent. , 



DESIRABILITY OF RETENTION OR SHEDDING OF INFESTED FORMS. 



Still another arrangement of general results may serve to show a 

 comparison between the four classes of forms and between hanging 

 and fallen forms. This arrangement is given in Table IV. It may 

 serve to indicate for the entire infested area whatever general advan- 

 tage there may be to the plant in the shedding or in the retention of 

 its infested forms. 



Table IV. — Summary of mortality results shown in Table III, hanging and fallen forms. 





Total 



num- 

 ber of 

 forms 

 exam- 

 ined. 



Total 



weevil 

 stages 

 found. 



Weevil stages 

 dead. 



Cause of death. 



Pro- 

 por- 



Class of fruit. 



Total 

 num- 

 ber. 



Per 



cent of 

 total 

 stages 

 found. 



Heat or 

 drying. 



Ants. 



Parasites. 



tion 



of 



forms 





Num- 

 ber of 

 stages 

 killed. 



Per 

 cent of 

 total 

 found. 



Num- 

 ber of 

 stages 

 killed. 



Per 



cent of 

 total 

 found. 



Num- 

 ber of 

 stages 

 killed. 



Per 

 cent of 

 total 

 found. 



to 

 each 

 weevil 



stage. 



Hanging forms: 

 Dried, hanging 



bolls 



Dried, hanging 



squares 



17,359 

 7,004 



5,433 

 4,230 



1,650 



2,227 



30.4 

 52.6 



40.2 



426 

 804 



7.8 

 19.0 



902 

 883 



1,785 



16.6 

 20.9 



18.7 



322 

 540 



862 



6.0 

 12.8 



3.20 

 1.66 



Totals, hang- 

 ing forms ... 



24,3(33 



9,663 



3,877 



1,230 



12.9 



9.0 



2.52 



Fallen forms: 

 • Fallen bolls... 

 Fallen squares 



22,085 

 39,908 



4,618 

 24,710 



1,523 



14,885 



33.4 

 60. 8 



527 

 6,201 



11.4 

 24.7 



951 

 7,806 



21.0 



32.8 



45 



778 



1.0 

 3.3 



4.91 

 1.62 



Totals, fall- 

 en forms . . 



62,593 



29,328 



16,408 



56.4 



6,728 



23.0 



8,757 



30.0 



823 



2.8 



2.13 



Summary of all 

 forms: 

 Hanging forms 

 Fallen forms. . 



24,363 

 62,593 



9,663 

 29,328 



3,877 

 16,408 



40.2 

 56.4 



1,230 



6,728 



12.9 

 23.0 



1,785 

 8,757 



18.7 

 30.0 



862 

 823 



9.0 

 2.8 



2.52 

 2. J3 



t Totals, . all 

 forms 



86,956 



38,991 



20,285 



52.3 



7,958 



20.5 



10,542 



27.2 



1,685 



4.3 



2. 23 



The possibility of weevil damage having any relation to the reten- 

 tion of forms by the plant may be settled by a study of the proportion 

 of weevil stages to each class of forms. 



The last column of the table shows the average proportion of each 

 class of forms to one weevil stage found. It must be borne in mind 

 that many squares and bolls are destroyed by the feeding of the 

 weevils in which no eggs have been deposited. Undoubtedly in a 

 great many cases a young larva may have died when no trace of its 

 presence could be found at the time the examination was made. 

 This would especially apply to the hanging forms. From the pro- 

 portions given it appears that, among hanging forms, twice 4 as many 

 bolls were examined for each weevil stage found as in the case of 

 squares, while among fallen forms the proportion is three to one. 

 This indicates that there is practically no difference in the proportion 



