24 BULLETIN 926, U. S. DEPARTMENT OF AGRICULTURE. 



velopment of the immature weevil after the sea-island squares drop- 

 ped off the plant was 10.4. 



The infested squares on the long-staple cotton required 12.3 days 

 from the date of the egg puncture to the falling of the infested 

 square. The time required for the immature weevil stages to com- 

 plete their development after the long-staple squares dropped off the 

 cotton plants averaged 10.5 days. One of the objections to the long- 

 staple varieties of cotton is the tendency of the infested squares to 

 hang on the plants, protecting the immature weevil stages to a cer- 

 tain extent from natural enemies and mechanical injury. 



A total of 92 male weevils of the first generation bred in sea-island 

 cotton squares required 2,006 weevil days or an average period of 









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■ 1 



- ' 



3m "''Jlm *'- KJiJ 







Fig. 10. — Shallow wooden troughs filled with crude oil to keep ants out of the weevil 

 hatchery, Madison, Fla. 



21.8 days for development of the immature stage. The 75 female 

 weevils bred from the same source required a total of 1,651 weevil 

 days or an average period of 22 days for development from egg to 

 adult. An average period of 21.9 days was required for the develop- 

 ment of both sexes of the first-generation weevils in sea-island cotton 

 squares. 



The 35 male weevils bred from long-staple cotton squares required 

 a total of 726 weevil days or an average period of 20.7 clays from 

 egg to adult. A total of 549 weevil days was required for the devel- 

 opment ofthe26 female weevils from long-staple cotton squares, or an 

 average of 21.8 days. The developmental period in long-staple cotton 

 squares lor both sexes from egg to adult averaged 20.9 days. 



A total of 61 male weevils of the first generation bred in upland 

 cotton squares under field conditions required 1,344 weevil days, or 

 an average period of development of 22 days. The 33 female weevils 



