1926 - Dunnam, E. W. Cotton boll growth in relation to boll weevil injury. J. Econ. Ent. 

 19(4):589-593. 



Evidence that as the cotton bolls grow older they are less susceptible to 

 injury by A. grandis, and the immunity at given ages varies with the variety. 

 There is no correlation between the number of feeding punctures or the number 

 of egg punctures and the percentage of cotton loss. Neither is there any relation 

 between the thickness of the boll and susceptibility to weevil damage, in spite of 

 the fact that the weevils lay fewer eggs in the thick-boiled varieties. The deter- 

 mining factor is the hardness of bolls, because varieties with the hardest bolls, 

 as determined by the number of grams pressure required to puncture them, show 

 also the lowest percentage of cotton loss. 



1926 - Gray, D. T. Report on entomological work, 1925-26. Ark. Agr. Expt. Sta. 

 B. 215:29-31. Nov. Fayetteville. 



Tests were made to determine the usefulness of tracing the spread of 

 infestations of the cotton boll weevil from areas infested by hibernating weevils, 

 the value of following the development of broods as an aid to timing dust applica- 

 tions, the effectiveness of dust as a barrier to migrating weevils, and the value 

 of repressing scattered infestations in the field and delaying the dusting over the 

 whole field until a serious threat of injury was first noticed. The tests were 

 made on two plantations that had previously been heavily infested. Practically 

 all the midseason infestation could be traced to areas infested by hibernating 

 weevils. No complete break was observed between the period of infestation by the 

 hibernating and first generations. Dusts applied on and around areas infested 

 by these weevils prevented the migration of the weevils and suppressed the 

 infestation to such an extent that the cotton continued to fruit until about August 

 12, when the general migration of the weevils began. 



1926 - Isely, Dwight. Early summer dispersion of the boll weevil. J. Econ. Ent. 

 19(1):108-112. 



The dispersion of the cotton boll weevil in a field, after the hibernating 

 weevils have become established, is periodic. Each period of dispersion 

 coincides with the emergence of a new brood of weevils. The spread of weevils 

 across a field is usually direct from plant to plant or row to row, and is not the 

 result of long flights. Newly emerged weevils do not usually migrate until sexual 

 maturity is attained. This information was used in locating infestations at the 

 beginning of the 2d and 3d periods of dispersion and in timing dust applications. 

 Small infested areas dusted before weevils reached sexual maturity resulted in 

 apparent extermination of infestation. 



1926 - Isely, Dwight. Early summer dispersion of boll weevil with special reference to 

 dusting. Ark. Agr. Expt. Sta. B. 204, 17 p. Feb. Fayetteville. 



Small areas in cotton fields infested by overwintering weevils are usually 

 difficult to locate until squares begin to flare and fall, or until the greatest ac- 

 tivity of this brood of weevils is past. It was found that these infested spots are 

 the centers of spread, and if they are marked, later infestations can be easily 

 traced to them. When the infested areas are marked and kept under observation, 

 it is easy to note the earliest activity of the weevils to develop in the field. The 

 relatively long nonmigratory feeding period of approximately a week gives ample 

 time for making dust applications, not only before weevils have spread but before 

 they have begun reproducing. Small infestations, both at Marianna and Varner, 

 dusted at this time, were apparently exterminated. 



1926 - Isely, Dwight. Insect pests in Arkansas, 1924-25. Ark. Agr. Expt. Sta. 

 B. 203:32-40, 3 fig. Fayetteville. 



"A short account is given of the dispersion and seasonal habits of the boll 

 weevil (A. grandis ) in cotton fields." 



1926 - Newell, W., E. F. Grossman, and A. F. Camp. The Mexican cotton boll weevil. 

 Fla. Agr. Expt. Sta. Tech. B. 180. May. 



Reviews history of boll weevil. Discusses biology of boll weevil in Florida. 

 Describes emergence from hibernation and migration. 



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