88 



From a study of Block I it is evident that infestation began some 

 time in July, since when first found it was entirely restricted to a 

 small area. A study of each block chronologically shows the steady 

 but rapid progress of the weevil, as does also a comparison of the 

 three blocks at the nearest possible dates. The tremendous activity 

 of weevils in midsummer and the possible rapidity of their spread is 

 clearly shown in this field. 



A study of two other fields yielded practically similar results. The 

 dates of examinations, with the percentages found in each case, will 

 be given. In field 3 there was found, upon June 2, 3 per cent of infes- 

 tation; on July 16, 25.9 per cent; on August 15, 65.9 per cent. This 

 field was from native seed and was planted about three weeks earlier 

 than field 4, which was of King seed, and just across a turn row from 

 field 3. In field 4 infestation began very late, as on August 8 there 

 appeared to be only 2 per cent and on August 15, 23.6 per cent, while 

 on August 2(j it had increased to 91.5 per cent, which is about the 

 usual percentage of maximum infestation. 



Under the conditions usually prevailing cotton will cease to make 

 when about two-thirds of the squares have become infested, since the 

 weevils have then become sufficiently numerous to attack nearly all 

 of the remaining clean squares before they have time to bloom and 

 form bolls. Even bolls which have set before this percentage of 

 infestation is reached are not entirely safe, as the smallest ones will 

 be more readily attacked by weevils, as they have greater difficulty 

 in finding uninfested squares. 



WEEVIL INJURY vs. SQUARE PRODUCTION. 



At the beginning of infestation the indications of the weevil's pres- 

 ence are inconspicuous. Even when considerably advanced most 

 farmers do not recognize the injury, and thus are led to believe that 

 the insect has not appeared. Among the most conspicuous indica- 

 tions of the weevil's presence may be mentioned the falling of infested 

 squares. As the squares remain on the plant after they become 

 infested fully as long as they lie upon the ground between the time 

 of their falling and the emergence of the weevil, it is plain that less 

 than half of the actually infested squares will ordinarily be observed. 

 Previous to falling infested squares gradually turn yellow, and in 

 most cases flare somewhat; but flaring is by no means as closely related 

 to weevil injury as might be supposed. As the percentage of infesta- 

 tion increases the great numbers of squares on the ground must attract 

 attention (PL XII, fig. 46). Shedding of squares may take place for 

 other reasons than the attack of the weevil, but in fair weather, when 

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

 probably present. As infestation approaches its climax there is a 

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

 ^ming age with many squares, but no blooms, the weevils are 



