117 



large numbers of squares are found upon the ground, the weevil is 

 probably present. As infestation approaches its climax there is a 

 great decrease in the number of blooms, and when a field is found 

 at blooming age with many squares but no blooms the weevils are 

 almost certainly abundant. The conditions named form the most 

 conspicuous indications of practically total infestation. During the 

 season of 1903 it was found that a condition of total infestation was 

 reached some time between August 1 and 20 in most fields within the 

 infested area. This condition is, as a rule, coincident with the appear- 

 ance in large numbers of weevils of the fourth generation. The exact 

 time will vary in different seasons, and even in adjacent infested fields, 

 because of varying conditions. 



Not only is the maximum number of weevils present in the field in 

 midsummer, but their capacity for injury is also greatest at that time. 

 Practically all of the crop that will be made must have been set before 

 this time. After this bolls will form only b}^ accident. 



A large series of examinations made by Messrs. Harris and Morrill 

 at Calvert, Tex., shows the very rapid increase in the percentage of 

 infested squares which usually takes place a few weeks earlier than 

 it did in 1903. The figures given in each column in the table show 

 also the closeness with which the weevil activity kept pace with the 

 formation of squares after the period of maximum infestation had 

 once been reached. The general influence of climatic conditions may 

 be seen by a comparison of the last two columns in the table, but this 

 point would be much more clearly shown by a series of examinations 

 made during the first half of the growing season, at which time tem- 

 perature and moisture would have greatest influence upon weevil 

 development and injury. One hundred squares were picked promis- 

 cuously in each block for the determination of the percentages given 

 in the columns for these 34 blocks, thus making a total of 17,000 

 squares examined. 



Table 1LXX.II.— Study of 



the 



infestation of the cotton fields at Calvert, 



Tex 



• 





Time of record. 



Block. 



1 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



20 



21 



22 



1903. 

 August 15-17 



72 

 96 

 93 

 92 

 94 



68 

 91 

 94 

 81 

 93 



64 

 96 

 92 

 89 

 90 



65 

 100 

 94 

 91 

 90 



71 

 96 

 97 

 97 

 91 



63 

 97 

 94 

 92 

 92 



66 

 98 

 93 

 91 

 88 



68 

 98 

 92 

 89 

 83 



59 

 90 

 95 

 89 

 92 



60 

 87 

 92 

 91 

 99 



59 

 90 

 94 

 94 

 96 



60 

 88 

 96 

 96 

 94 



46 

 92 

 88 

 96 

 95 



46 

 95 

 89 

 94 

 93 



^-i 



September 2-4 



89 



September 14-17 



90 



October 1-3 



91 



October 22-24 



91 







Time of record. 



Block. 



23 



24 



25 



2G 



27 



27 a 



28 



29 



30 



31 



32 



33 



50 



51 



52 



1903. 

 August 15-17 



48 

 69 

 92 

 94 

 95 



50 

 94 

 91 

 94 

 91 



54 

 91 

 92 

 90 

 89 



47 

 91 

 94 

 96 

 98 



49 

 88 

 93 

 93 

 94 



52 

 93 

 92 

 94 

 91 



51 

 95 

 90 

 92 

 97 



58 

 91 

 96 

 92 

 90 



54 

 91 

 94 

 95 

 97 



54 

 93 

 96 

 99 

 95 



57 

 93 

 93 

 94 

 97 



55 

 97 

 94 

 96 

 93 



62 

 89 

 93 

 92 

 96 



66 

 94 

 92 

 87 

 97 



58 



September 2-i 



96 



September 11-17 . . . 



95 



October 1-3 



89 



October 22-24 



97 







