In October 1999, 0% to 100% mortalities of boll weevils, Anthonomus grandis Boheman, were determined 2, 4 and 8 hours after placing laboratory reared boll weevils in S&S and Precision Plastic (PP) traps containing yellow colored Plato Industries Insecticide Chips (PIICs) or Hercon Strips (HS) which contained 60 mg of dichlorvos (DDVP). Boll weevils escaped from both traps on "0" day. In August 2000, 100% mortality of marked, lab reared boll weevils was determined after 24 hours using the two dispensers described above, a blue colored PIIC and 60 and 90 mg PII Square dispensers of DDVP in S&S Traps. In both tests the dispensers were individually placed in traps on day "0" and remained there for 28 days. There was no significant difference in the 8% to 14% "escapes" from S&S traps with five different dispensers. The 90 mg dispenser had the lowest percentage "escapes". After 24 hours, 90 to 100 "wild" boll weevils per S&S trap were captured on all sample dates. Residues of DDVP from all dispensers determined on 0, 7, 14, 21 and 28 days showed equal rates of loss. Range of loss for the five dispensers was 43 to 61%, 51 to 58%, 64 to 78% and 64 to 83% after 7, 14, 21 and 28 days, respectively. It was determined that residues lost in each 24 hours were about 100 µg of DDVP per day.