Mark-recapture data indicate that late-season boll weevil movement within a small cotton field treated with the insecticides Guthion or Karate, the defoliant Def, or their combinations, was very limited over a 7-10 day period, with most weevils remaining in the row in which they were released or in immediately adjacent rows. Although within-field movement was relatively restricted, a large percentage of weevils dispersed completely out of the field, ranging from 51 to 76% of the beginning population depending on treatment. Thus, weevils that moved at all tended to leave the field entirely. We conclude that the magnitude of movement within the field was low enough that it was not a significant factor confounding results of the efficacy studies of Greenberg et al. (2001b). The vast majority (99.8%) that left the field did not respond to the surrounding pheromone traps. Although dispersal from the field was high, data from weevils collected and held for 24 hr in the laboratory suggest that many emigrants died outside the field within 4 d post-treatment. This was especially true in the case of weevils treated with Def+Karate, in which only 3% of weevils that dispersed were predicted to have survived beyond 4 days. Estimates of percentage total mortality for the five treatments were calculated from the sum of those estimated to have died in the plots and those estimated to have dispersed and then died [Karate Z (full rate) 52.6%; Guthion (2-rate) 51.3%; Def
26.3%; Def+Karate 93.4%; Def+Guthion 71.1%].