42 



naxiraum of 704 larvae per acra in untreated check fields. During the study, the 

 incidence of the tobacco budworm was greater in the Heliothis population in 

 Stonewall County (66 percent) than in either Kent (36 percent) or Dickens County 

 (26 percent) where the bollworm was the dominant species. 



73. ; Reeves, R. E.; Almand, L. K.; Hardee, D. D.; and Cross, W. H. 1970. 

 Studies of the boll weevil populations and their movement in the High 

 and Rolling Plains of Texas using male-baited traps, 1968. Tex. Agric. 

 Exp. Stn. Misc. Publ. MP-948, 8 pp. 

 Traps baited with live male boll weevils, Anthonomus grand is Boheman, as the 

 source of pheromone were evaluated for effectiveness in survey and population 

 studies with boll weevils in 1968 in the High and Rolling Plains of Texas. 

 A trapline along the "Caprock", the escarpment defining the eastern and south- 

 eastern limits of the High Plains, was used to determine the number of weevils 

 dispersing from the Rolling Plains to infest High Plains cotton fields and to 

 compare the size of weevil populations above and below the Caprock. Weevils 

 were captured in larger numbers below than above the Caprock where weevils 

 were captured more regularly on traps located near canyons. This indicated 

 that these canyons may serve as important routes for weevils dispersing from 

 the Rolling Plains to infest High Plains cotton fields. Records rrr»m traps in 

 counties supporting weevil populations of various sizes were similar to records 

 from actual field Infestation counts in comparing the relative abundance of 

 weevils. More weevils were captured on traps near the most heavily infested 

 cotton fields. Traps placed in a cotton field not infested with weevils were 

 effective in detecting incipient infestations of weevils developing late in the 

 season and in studying the seasonal population increase. A total of 3,882 weevils 

 was captured in 8 1/2 weeks in the fall on 16 traps j.n a heavily wooded area 3.2 

 miles from the nearest cotton field. 



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