Screens treated with adhesive were set up between May 2 8th and June 2d, 

 and observed daily. Records were kept to determine the effect on dispersal of 

 relative abundance of weevils, supply of food, and distance from breeding- 

 places, and height of the cotton plants. 



The results secured, though not conclusive, indicate that there was no 

 relation between the spring infestation in 1928 and the situation of scattered 

 cotton plantings in 1927, though distance from a supplementary source of 

 weevils may be an important factor in early spring infestations. 



1929 - Fenton, F. A., and E. W. Dunnam. Biology of the cotton boll weevil at Florence, 

 S. C. U. S. D. A. Tech. B. 112, 75 p. 



Climate exerts an important influence on the seasonal cycle. Temperatures 

 of 11°F. or lower are unfavorable to overwintering weevils; hot, dry summers 

 are also unfavorable. Squares punctured once remained on the plant for an aver- 

 age of about a week. Those more than 6 days old were always preferred for 

 oviposition. For feeding, the younger the boll, the more frequently it was punc- 

 tured. Four generations occurred in a season, the first and second being large, 

 and the third and fourth incomplete. The maximum emergence and oviposition of 

 the different generations took place before the middle of August. Development of 

 the weevil was most rapid during the period of maximum production of squares 

 and was less after the plants had shed most of the squares and young bolls. The 

 longevity and pre-oviposition periods of weevils in cages under varying condi- 

 tions is discussed. Trap-crop records indicate that flight dispersal began about 

 mid-July in 1925 and 1926. Temperature influenced flight to some extent, even 

 after it was initiated, more weevils flying at high temperatures. Dispersal was 

 also correlated with the percentage of infestation. 



1929 - Grossman, E. F. Biology of the Mexican cotton boll weevil. III. The mechanism of 

 grub feeding. Fla. Ent. 13(2):32-33. 



It is suggested that the larva of Anthonomus grandis does not eat its way out 

 of the cotton boll because it prefers the soft interior to the hard shell and, there- 

 fore, mechanically avoids the numerous dangers to which it would be exposed on 

 the exterior of the boll. In experiment with infested bolls in which the outer 

 shells had been made as soft as the contents, or the latter dried as hard as the 

 shells, the grubs in both cases began to bore through the walls. 



1929 - Grossman, E, F. Biology of the Mexican cotton boll weevil. IV. Duration of 



fertility after copulation. Fla. Ent. 13(3):41-43. 



Females of Anthonomus grandis Boh. were isolated after mating, and kept 

 for various periods in artificial hibernating quarters at a temperature of 55°F. 

 They were then placed on fresh cotton squares in an incubator at 80°F. Fertile 

 eggs were laid for periods up to almost 7 months after mating had occurred. 



1930 - Calhoun, P. W. Time of hatching first generation boll weevils relative to appear- 



ance of blossoms. Fla. Ent. 14(4):72-75. 



In order to be able to predict when first generation weevils might be ex- 

 pected to emerge, squares of an upland and a sea- island variety of cotton were 

 measured between May 29th and June 6th. The time between the date of meas- 

 uring and the date of blossoming was recorded and correlated with the period 

 required for a weevil to develop from the egg in the field in Florida; that is, 

 21-22 days. It was found that for a weevil to emerge from the upland cotton 

 before blossoming time, it would have to develop from rather small squares of 

 about 4.5 mm. in diameter at the time of oviposition. Weevils do not ordinarily 

 develop in squares smaller than this. Very small squares dry so readily after 

 they fall from the plants that the larvae they contain die. On the other hand, 

 weevils of the first generation may easily emerge within 3 or 4 days after the 

 first blossoms appear, as squares of 5.5 to 6.0 mm. can easily produce 

 weevils in that time, except under unfavorable weather conditions. Although 

 only one variety of upland cotton was tried, it was thought that other standard 

 varieties would not show sufficient differences to be of importance. Some of 



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