The formamidine, Ovasyn 1.5E (amitraz), has the potential to aid cotton producers in the management of Lepidopteran pests of cotton. It has ovicidal and larvicidal activity, modifies locomotor and ovipositional behavior of pests, and synergies some insecticides against the bollworm (BW), Helicoverpa zea (Boddie), and tobacco budworm (TBW), Heliothis virescens (F.). In tests conducted in Northeast Louisiana, amitraz applied at 0.25 lb AI/acre produced 71, 73 and 87 percent egg mortality at 4, 24 and 48 hours posttreatment, respectively. Residual activity was excellent and these results are similar to those of chlordimeform (CDF). Test averages over years (1987-1990) and locations indicated that amitraz (0.25 lb AI/acre) provided 36 percent residual ovicidal activity, Larvin 3.2F (thiodicarb, 0.25 lb Al/acre) had a rating of 30 percent and Curacron 8E (profenafos 0.25 lb AI/acre) produced only 6 percent ovicidal control at 48-hours posttreatment against the BW-TBW complex. At the Northeast Research Station (Macon Ridge Branch), the efficacy of Karate 1E (lambda-cyhalothrin, 0.025 lb AI/acre) was significantly increased by 28 percent in a mixture with amitraz (0.125 lb AI/acre). At the Northeast Research Station (St. Joseph Branch), thiodicarb (0.6 lb AI/acre) was enhanced by 32 percent in a mixture with amitraz (0.125 lb AI/acre). The benefits of amitraz in resistance management was observed in two separate on-farm situations in 1990. At Hebert and Lake Providence, LA, TBW field control failures occurred and TBW resistance was subsequently documented to the carbamates, organophosphates and pyrethroids. Applications of amitraz (0.2 lb AI/acre) at Hebert, decreased BW-TBW oviposition by 18-33% in treated plots. At Lake Providence, the binary mixture of Bolstar 6E (sulprofos 1.0 lb AI/acre) and amitraz (0.125 lb AI/acre) prevented a control failure compared to the binary mixture of sulprofos (0.75 lb AI/acre) and thiodicarb (0.25 lb AI acre).