second. An average late-season population of 

 about 1,300 weevils per acre resulted in severe 

 yield loss. In the treated fields, populations were 

 generally held well below 1,000 insects per acre. 

 Organophosphorus insecticides were more ef- 

 fective for the control of overwintered weevils 

 than the chlorinated hydrocarbon mixture at 

 the dosage used. 



181. Walker, J. K., Jr., and Hanna, R. L. 

 Development of populations of the boll weevil 

 in fields treated with various insecticides dur- 

 ing 1959, I960, and 1961. Jour. Eton. Ent. 56 : 

 350-356. 1963. 



Seasonal populations were carefully sampled 

 in a number of small contiguous fields where 

 control programs with different insecticides 

 were being conducted. Cotton fruiting and 

 fruit damage in these and in untreated areas 

 were recorded. Organophosphorus compounds 

 were generally more effective for control of 

 overwintered weevils than other types of insec- 

 ticide used, but continued emergence of weevils 

 after squaring began during 1960 and 1961 re- 

 duced effectiveness of programs depending on 

 a single application for the control of overwin- 

 tered weevils. Continuously high populations in 

 the untreated areas resulted in greatly reduced 

 boll set, but the emergence of large numbers of 

 weevils in the treated fields that increased 

 square damage temporarily did not reduce boll 

 set. However, in the treated areas higher per- 

 centages of punctured squares were usually fol- 

 lowed by higher percentages of weevil-damaged 

 bolls. The rate of population increase from gen- 

 eration to generation and the amount of 

 damage caused by each weevil depended to a 

 great extent on the number of squares on the 

 cotton and the intensity of competition for 

 those squares. 



In untreated fields in 1960 and 1961 first- 

 generation increases over overwintered popula- 

 tions were about threefold and twofold, re- 

 spectively. 



182. Walker, J. K., Jr., and Pickens, L. G. 

 Egg deposition by boll weevils isolated from 

 males during hibernation period and after 

 spring emergence. Jour. Econ. Ent. 55: 268- 

 269. 1962. 



Three hundred field-collected female boll 

 weevils were isolated from males in small 

 screen cages and buried in ground trash during 

 fall and winter. The cages were removed from 

 the ground trash the following March and 70 

 weevils were alive. Thirty-four were healthy. 

 Twenty-nine of these deposited fertile eggs. 

 Apparently sperm from fall matings remained 

 viable during winter months. 



Thus early-spring insecticide treatments to 

 reduce numbers of females would be more im- 

 portant than other methods of control designed 

 to reduce chances of additional spring matings. 



183. Walker, J. K., Jr., and Shipp, O. E. 

 Occurrence of developmental stages of the boll 



weevil in cotton bolls during the dormant sea- 

 son of 1962-63 at College Station. Tex. Agr. 

 Expt. Sta. Prog. Rpt. 2282, 5 pp. 1963. 



February and March examinations of cot- 

 ton bolls heavily infested with immature stages 

 of the boll weevil in early winter showed sig- 

 nificant numbers of all stages of the pest were 

 alive as late as March 15. Some of the surviving 

 adults contained fat despite having never fed 

 in the adult stage. Surviving pupae contained 

 more fat than pupae reared on an artificial lab- 

 oratory diet. Successful overwintering in this 

 manner occurred more times where a hardened, 

 firm cell had been formed around the develop- 

 ing insect. The survival of small numbers of 

 boll weevils, especially in South or West Texas, 

 appears possible in this manner. 



184. Watson, T. F., and others. Effect of 

 several insecticides and application schedules 

 on cotton insect control. Ala. Agr. Expt. Sta. 

 Prog. Rpt. Ser. 88, 5 pp. 1965. 



F. A. Arant, W. G. Eden, and M. C. Sconyers, 

 joint authors. 



The only insects causing serious damage to 

 cotton in the Wiregrass Area of Alabama dur- 

 ing the 4-year period of 1961 through 1964 

 were boll weevil and bollworms. This investiga- 

 tion revealed that insecticidal treatment was 

 essential at some time during the growing sea- 

 son to control these pests. Control during the 

 major fruiting period was of greatest impor- 

 tance. Yields of cotton were not increased by 

 control of minor pests. 



185. Watson, T. F., and Sconyers, M. C. 

 Comparison of insecticide application schedules 

 for control of cotton insects. Jour. Econ. Ent. 

 58: 1124-1127. 1965. 



Toxaphene-DDT, endrin-methyl parathion, 

 and azinphosmethyl-DDT were used in a 3- 

 year study, with six different control schedules. 

 Yield losses were caused only by boll weevil, 

 bollworm, and tobacco budworm. There were 

 no significant differences among the yields 

 from the application-schedule treatments, but 

 all were highly significant when compared with 

 the untreated checks. 



186. Weiden, M. H. J., Moorefield, H. H., 

 and Payne, L. K. O-(methylcarbamoyl) ox- 

 imes: a new class of carbamate insecticide- 

 acaricides. Jour. Econ. Ent. 58: 154-155. 

 1965. 



Preliminary toxicity data are presented for 

 several insects for 3-chloro-6-cyano-2-norbor- 

 naone O-(methylcarbomoyl) oxime and 2- 

 methyl-2-(methylthio) propionaldehyde O- 

 (methylcarbamoyl) oxime. The LD 50's for the 

 boll weevil were 5 and 0.1, respectively. 



187. Wilkes, L. H., Adkisson, P. L., and 

 Cochran, B. J. Use of an air-carrier sprayer 

 for cotton insect control. Tex. Agr. Expt. Sta. 

 Prog. Rpt. 2205, 3 pp. 1961. 



In experiments conducted in 1960 near Col- 

 lege Station, Tex., comparable control of cotton 



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