Field tests (1993-96) were conducted in North Louisiana to evaluate the effects of terminating insect control strategies for bollworm/tobacco budworm (BW/TBW) and boll weevil at selected intervals on seedcotton yields. The termination intervals were based on cotton plant development measured as plant mainstem nodes above white flower (NAWF) and heat unit (HU) accumulation. Treatment termination intervals based on crop development rules and weather oriented rules included NAWF = 5, NAWF = 5 + 200 HU, NAWF = 5 + 350-400 HU, NAWF = 5 + 500-600 HU and NAWF = 5 + 600-800 HU. In 1993, 1995, and 1996, there were no significant differences in yields among termination intervals. In 1994, yields increased as insecticides were applied up to NAWF = 5 + 400 HU. Plots with insecticides terminated at this interval produced yields that were significantly higher than that for plots when treatments were terminated earlier.