The operation of sex-pheromone baited traps placed adjacent to cotton was compared with the operation of traps placed directly in cotton fields. The studies were conducted for tobacco budworm (TBW), Heliothis virescens (F.), and bollworm (BW), H. zea (Boddie), in three commercial cotton fields located in Burleson County, TX, ca. 15 km west of College Station, TX. The producers carried out their normal production practices of cultivation, irrigation and pesticide application during the tests.

The 75-50 wire mesh cone traps as described by Hartstack et al. (1979) were used for both species. Baits recommended by Lopez et al. (1987) were used: a 1.27 x 2.54 cm Hercon^® laminated plastic pheromone dispenser (Hercon Environmental Inc., Emigsville, PA 17318) with 1.25 mg four component pheromone for BW, and a 1.27 x 1.27 cm molded black polyvinyl chloride dispenser prepared by Don Hendricks (Hendricks et at 1987) with 6.25 mg two-component pheromone for TBW (similar baits are available from Scentry Inc., Buckeye, AZ 85326).

The evaluation compared traps at three positions: 5 in into the cotton, on the edge of the cotton, and 5 in away from the cotton. For each test, nine sites were designated at 100 in intervals along one side of a cotton field. One trap was placed at each site. Positions were alternated between sites such that three sites had traps at each position each day. Moths were counted and removed from the trap and the positions of the traps were rotated daily, so at the end of a three-day block, the trap at each site had been operated at each position. The test was carried out at separate times for the two species: 30 days (10 blocks) for BW and 39 days (13 blocks) for TBW.

The three fields were selected to test for possible differences between upwind, downwind and crosswind situations, but there were no differences indicated between the positions because of wind. Statistical tests also indicated no significant differences between trap sites within each field. The data for each species did indicate a significant difference between the catches inside the field and those at the edge or outside the field. No significant difference was shown between catches in traps at the edge of the crop and in traps 5 m outside the crop so data for those treatments were combined and are referred to as "adjacent" in further analysis.