Ciba Crop Protections' Curacron® resistance monitoring program was begun in 1993 and has now completed the third cotton growing season. In 1995 field collections of tobacco budworm adults (Heliothis virescens F.) from several areas throughout the Cotton Belt were made. Eggs from these moths were shipped to Ciba's Vero Beach Research Center in Vero Beach, Florida, by overnight air where IRAC Method #7 was used to conduct discriminating dose and multi-dose bioassays with Curacron 8E against late 2nd instar larvae. In discriminating dose bioassays field strains of larvae from McGehee, Arkansas, and Cheneyville, Louisiana, showed slight increases in resistance gene frequency from 1994 to 1995, with a field strain of larvae from Tifton, Georgia, showing the highest increase in resistance gene frequency. However, this occurred during the two year period from 1993 to 1995, with no data obtained in 1994. In contrast to these increases in resistance gene frequency, a strain of larvae from Friars Point, Mississippi, showed a marked decrease. Multi-dose bioassays showed slight to moderate increases in tolerence to Curacron® with larvae from McGehee, Arkansas, (1.2-fold) from 1994 to 1995 and Tifton, Georgia, (3.2-fold) from 1993 to 1995. Increases in sensitivity were found in field strains of larvae from Cheneyville, Louisiana, and Greenville, Mississippi.