1955 - Roussel, J. S„, and D. F„ Clower. La. Agr. Expt. Sta. C. 41, 9 p. 



Boll weevils became difficult to control in some areas of Louisiana late in 

 the summer of 1954. Adverse climatic conditions, including high temperatures, 

 high wind velocities, and low humidities, were considered responsible for the 

 poor control obtained. 



Under entirely different climatic conditions in 1955 even more difficulty was 

 experienced in obtaining control. Work conducted in the laboratory, plus supporting 

 work in the field, showed that a high degree of resistance to the chlorinated 

 hydrocarbon insecticides had developed in boll weevil populations in some areas 

 of Louisiana as follows: Northeast Louisiana to include Waterproof, St. Joseph, 

 Tallulah, and large areas of East Carroll Parish; Ouachita River Valley south of 

 Monroe; and Red River Valley, including parts of Caddo, Red River, Bossier, 

 Grant, Natchitoches, and Rapides Parishes. 



1956 - Roussel, J. S., R. V. Bielarski, and D. F. Clower. The status of chlorinated 



hydrocarbon resistance in the boll weevil in Louisiana. La. Agr. Expt. Sta., Dept. 

 Ent. Spec. Release No. 1. July 5. 



This report summarizes information obtained from topical treatments of 

 Guthion and Endrin on overwintering boll weevil populations collected at several 

 locations in Louisiana and on first generation boll weevils reared from infested 

 squares collected in the same area. Results show that in areas where resistance 

 to chlorinated hydrocarbons was high in 1955, it has persisted in 1956. 



1956 - Walker, J. K. Jr., B. G. Hightower, R. L. Hanna, and D. F. Martin. Control of 



boll weevils resistant to chlorinated hydrocarbons. Tex. Agr. Expt. Sta. Prog. 

 Rpt. 1902. Nov. 7. 



Chlorinated hydrocarbon failed to give commercial control of boll weevil in 

 several fields in the Brazos River Valley near Hearne in 1956. Calcium arsenate 

 and several phosphorus compounds were effective in controlling these populations. 

 Laboratory tests confirmed these differences. 



1957 - Bielarski, R. V., J. S. Roussel, and D. F. Clower. Biological studies of boll 



weevils differing in susceptibility to the chlorinated hydrocarbon insecticides. 

 J. Econ. Ent. 50(4):481 -482. 



Biological studies of 2 strains of the boll weevil, one quite susceptible and 

 a second highly resistant to endrin, showed no difference in the average number 

 of eggs produced per female per day, duration of larval stadia, pupal stage, or 

 time required to develop from egg to adult. This is strong evidence that selection 

 for resistance in the population was carried on independently of inheritance for 

 other biological characters. 



1957 - Brazzel, J. R., L D. Newsom, J. S„ Roussel, R. C. Gaines, and T. Cascio. The 

 effect of food on fat accumulation of resistant and susceptible boll weevils. 

 J. Econ. Ent. 50(4):459-462. 



Fat content was determined for resistant and susceptible boll weevils reared 

 in the laboratory and fed on blossoms, bolls, or squares. Fat content, as used in 

 this study, was the total ether-extractable material expressed as a percentage of 

 the dry weight of the boll weevils. Total fat and rate of accumulation by resistant 

 and susceptible boll weevils were approximately equal throughout the feeding 

 period. Unfed boll-reared boll weevils were fatter than unfed square-reared boll 

 weevils and approximately the same difference in fat content was evident after 

 feeding for 20 days. Both boll-reared and square-reared boll weevils accumulated 

 more fat when fed bolls, less on blossoms, and least fat on squares. 



1957 - Furr, R. E„, E. P. Lloyd, and M. E. Merkl. Delta study of boll weevil resistance. 

 Miss. Farm Res. 20(4):5. April. 



1. There was a difference in kill with the same insecticide when weevils 

 were obtained from different locations. 



2. Mixtures of certain phosphate and chlorinated hydrocarbon insecticides 

 gave better kill in field than either alone. 



151 



