the sea-island varieties, however, might possibly have a pre-bloom 

 period sufficiently long to permit first generation weevils to begin emerging 

 several days before the first blossoms appear. Ordinarily they do not emerge 

 so early in sufficient numbers to cause damage, as a large percentage of the 

 eggs first laid are killed by the hot sun before the cotton plant is large enough 

 to furnish sufficient shade. 



If rainy weather prevails from the time the infested squares begin to 

 fall, and no hot sunny weather occurs, first generation weevils begin to emerge 

 by the time the blossoms appear or shortly afterwards, and may easily become 

 sufficiently numerous within 3 weeks to puncture many of the bolls. 



1930 - Grossman, E. F. Biology of the Mexican cotton boll weevil. V. Diurnal observa- 

 tions of the emergence of boll weevils from their hibernation quarters. Fla. Ent. 

 14(3):45-52. 



Experiments in Florida showed that A. grandis Boh, usually leaves its hi- 

 bernating quarters during the daytime, though emergence at night was also ob- 

 served. Owing to the fact that in every year individuals emerge daily from 

 March 1 to mid-July, regardless of climatic conditions, it appears that the 

 weevils appear when they are physiologically ready to do so, and that daylight, 

 rainfall, and rises of temperature have little effect in accelerating the process. 



1930 - Grossman, E. F. Biology of the Mexican cotton boll weevil. VI. Some humidity and 

 temperature effects on development and longevity. Fla. Ent. 14(4):66-71. 



Owing to the difficulty encountered in keeping adults of A. grandis Boh. alive 

 in low temperature incubators equipped with brine coils, experiments were 

 undertaken to determine the optimum range of relative humidity necessary for 

 successful hibernation in artificially cooled environments. Relative humidities 

 ranging from 1% to 100% were obtained by means of sulphuric acid solutions. The 

 length of life of adult weevils was determined at various temperatures from 2°C. 

 to 27°C. (35.6° to 80.6°F.), and data on hatching and development of 21° to 27oc. 

 (69.8° to 80.6°F.), with 16 to 19 different humidities. The results are shown in 

 detail in tables. For a period of several days the adults can withstand any 

 percentage of humidity, though a range between 61 and 98 was necessary for 

 continued activity. 



1930 - Webb, J. L., and F. A. Merrill. Cotton or weevils. U. S. D. A. Misc. Pub. 35 



(revised), 16 p. 



A popular account of the bionomics and control of the cotton boll weevil in 

 the United States. 



1931 - [Grossman, E. F. Biology of the Mexican cotton boll weevil. VII. The boll weevil 



in artificial hibernation quarters. Fla. Ent. 15(2):2l-27. 



A new type of cage is described in which various factors influencing hiber- 

 nation of Anthonomus grandis Boh, could be observed. The weevils were nega- 

 tively geotropic when seeking hibernation quarters, and it was probably this 

 influence that caused the majority to choose the uppermost of a series of 

 horizontal tubes containing Spanish moss. Moisture also seems to attract the 

 weevils, so much so that in Florida it has been necessary to move cotton plant- 

 ings away from areas near ponds and containing trees bearing Spanish moss. 

 The weevils hibernated there very successfully and reappeared in such numbers 

 that cotton could not be produced economically. Hibernation of the weevils in 

 cages exposed to varying temperature and relative humidity appears to be as 

 successful as in cages kept at constant optimum temperature and relative hu- 

 midity. , 



131 



