BIOLOGY OF THE MEXICAN COTTON BOLL WEEVIL. 7 



bolls being collected under similar field conditions. These records 

 were continued throughout August and to the 1st of September. 

 Table II shows the results of this examination : 



Table II.- 



-Record of iveevil infestation in green bolls of sea-island and upland 

 cottons, Madison, Fla. 



Date of examination. 



Total 

 num- 

 ber 

 bolls 

 exam- 

 ined. 



Upland cotton 

 bolls. 



Num- 

 ber 

 clean. 



Num- 

 ber 

 punc- 

 tured. 



Sea-island cotton 

 bolls. 



Num- 

 ber 

 clean. 



Num- 

 ber 

 punc- 

 tured. 



July 19.. 

 July26.. 

 Aug. 4. . . 

 Aug. 11.. 

 Aug. 20. . 

 Aug. 25. . 

 Sept.l... 



200 

 200 

 200 

 200 

 200 

 1600 

 200 



74 

 81 

 69 

 69 

 61 

 166 

 29 



26 

 19 

 31 

 31 



39 



'334 



71 



Total 



Per cent punctured. 



1,800 



529 



171 

 24.4 



551 

 50.09 



1 500 sea-island. 



2 33 per hundred. 



: 67 per hundred. 



A careful study of Table II shows that the number of weevils 

 attacking sea-island bolls was far greater than the number attacking 

 upland bolls. Observations in the field also show that a great many 

 more weevils are to be found feeding on the sea-island bolls than on 

 upland cotton bolls. 



LONGEVITY OF ADULT BOLL WEEVILS ON UPLAND AND SEA- 

 ISLAND COTTON. 



The length of time adult weevils live on upland cotton has been 

 determined for several different times and places. The object of 

 the longevity tests at Madison, Fla., was to determine whether there 

 was any considerable difference in the length of life of weevils fed 

 on upland and sea-island cottons. 



Table III gives the observations on the longevity of the weevil 

 when fed upon different parts of the upland cotton plant. The 

 maximum longevity of 84 days was shown by a male weevil that had 

 hibernated over the preceding winter and emerged from hibernation 

 during the month of April. The average longevity for hibernated 

 weevils without food was 12.7 days, compared with an average of 

 18.8 days for hibernated weevils fed on cotton plantlets. Adult 

 weevils of the first and second generations lived an average of 24.3 

 days on cotton squares and 12.3 days on green cotton bolls. 



Table IV gives the data concerning the longevity of boll weevils 

 on sea-island cotton. The maximum longevity on sea-island cotton 



