In laboratory, greenhouse, and field tests, we determined effects of combining the defoliants Def and / or Dropp with half rates of the insecticides Karate or Guthion and the combination of Def+Dropp alone on boll weevil mortality and quality of defoliation. Def, 0.5x+Dropp, 0.5x, showed a slight toxic effect against boll weevil, while Def, 1.0x+Karate, 0.5x; Def, 1.0x+Guthion, 0.5x; and Def, 0.5x+Dropp,0.5x+ Guthion, 0.5x, provided control of boll weevil as good or better than full-rate Guthion or Karate alone. Treatment with Def, 0.5x+Dropp, 0.5x significantly increased defoliation compared to full rates of Def or Dropp alone, and provided adequate defoliation for approximately the same cost per acre.