330 



week o£ July and continuing to the end of squaring. No economic benefits were 

 derived by exceeding minimum recommended dosages or reducing maximum recommended 

 intervals. Statistically significant but relatively small practical differences 

 in boll weevil control, square production, and yield were noted among treatments 

 of azinphosmethyl-DDT, carbaryl, and toxaphene-DDT. In comparison with nearby 

 untreated cotton, the preventive treatments reduced the boll weevil population 

 81% in early and mid-season and 77% in late season. The treatments increased 

 the yield of seed cotton 1378 lb/acre, averting a 42% reduction in boll set and 

 41% boll damage. In comparison with a treatment schedule based upon 10% square 

 infestation, the preventive schedule (1) reduced the late season boll weevil 

 population 88%, (2) shortened the fruiting period about 10 days, (3) was easier 

 to follow, and (4) required only about half as many applications. Similar yields 

 were obtained with the 2 schedules. 



638. Mitchell, E. B. 1978. Pheromone trapping as an index for initiating 

 control of boll weevils. Proc. 1978 Beltwide Cotton Prod. Res. Conf., 

 pp. 115-116. 



Pheromone traps have been tested primarily for suppressing or controlling a 

 weevil population and for survey and detectt'ou. They have proved to provide 

 the most effective available method of detecting light weevil inyitration; 

 however, their value for suppression and control is not clear at the present 

 time. 



639. , and Hardee, D. D. 1974. In-field traps: a new concept in survey 

 and suppression of low populations of boll weevils. J. Econ. Entonol. 

 67: 506-503. 



Grandlure-baited traps placed in the field captured boll weevils, Anthononus 

 grand is Boheman, when manual surveys failed to detect signs of infestations. 

 An aggregating response was obtained from both sexes in early and late season 



