BULLETIN 358, TJ. S. DEPARTMENT OF AGRICULTURE. 



Table I. — Duration of life of boll zveevils. Observations of 1913-14- 



VARIETY GRANDIS "WITHOUT NORMAL FOOD. 











Aver- 



Maxi- 







Season and period. 



Food. 



No. of 



weevils. 



Weevil 

 days. 



age 

 lon- 

 gevity. 



mum 

 lon- 

 gevity. 





Remarks. 



1913. 









Daus. 



Daiia. 







Sept. 24 to Oct? 



Hibiscus leaves.. 



4 



24 



6.0 



13 



In paper 



bags on plants. 



Sept. 24 to Oct. 10... 



Hibiscus bolls... 



4 



25 



6.3 



16 



Do. 





Do 



Hibiscus leaves, 

 flowers, and 



4 



46 



11.0 



16 



Do. 











bolls. 















Sept. 24 to Oct. 9.... 



Okra buds and 

 fniit. 



8 



44 



5. .5 



15 



Do. 





Sept. 24 to Oct. 12. . . 



Okra fruit 



8 



75 



9.4 



18. 



Do. 





Sept. 24 to Oct. 8.... 



Okra leaves 



4 



26 



6.5 



14 



Do. 





Sept. 24 to Oct. 10... 



Thurberia leaves 



4 



42 



10.5 



16 



Do. 





Sept. 24 to Oct. 4 



Thurberia tips 

 and buds. 



4 



34 



8.5 



10 



Do. 





Sept. 24 to Oct. 8-.-- 



Thurberia 

 squares. 



4 



29 



7.3 



14 



Do. 





Total longevity on m 



ilvaceous plants. . 



44 



345 



7.8 



18 





VARIETY GRANDLS WITH NORMAL FOOD. 



1914. 



Aug. 6 to — 



July 15 to Aug. 1 



JiuieS to Oct. 28 



June 13 to Oct. 28... 



Cotton leaves 



Cotton bolls 



Cotton squares.. 

 do 



Total on normnl food . 



40 



390 



9.8 



17 



20 



210 



10.5 



16 



24- 



1,106 



46 



107 



24 



1,118 



46.6 



100 



108 



2,824 



26.1 



107 



In glass tumblers. 



Do. 

 Females in glass tumblers. 

 Males in glass tumblers. 



Ill the abnormal food studies the weevils hved an average of 6 

 days on Hibiscus leaves; 11.5 days on Hibiscus leaves, flowers, and 

 fruit; 6.25 days on Hibiscus tips; 6.5 days on olvra leaves; 9.4 days 

 on okra fruit; 11 days on okra leaves, flowers, and fruit; 10.5 days 

 on Thurberia leaves; 8.5 days on Thurberia tips and buds, and 7.3 

 days on Thurberia squares. These records are all low, probably due 

 to the experimental methods, as the weevils were all placed upon the 

 food in paper bags and later observations show that the method 

 apparently causes an early death. 



SEASON OF 1915. 



The studies of 1915 compare the longevity of grandis weevils on 

 moist sand with no food, on moist sand with okra and Hibiscus, on 

 moist sand with different parts of the cotton, and also thurheriae, on 

 moist sand with okra, wdth cotton bolls, and with cotton squares. 

 The species of Hibiscus used were H. militaris and H. moscheutos. 

 The results are given in Table II. 



