Laboratory assays were conducted to study the dosage-mortality profiles of 1st, 3rd, and 5th instar Heliothis virescens larvae exposed to commercial formulations of a bacterial (Bacillus thuringiensis--javelin), a viral (Heliothis nuclear polyhedrosis virus--Elcar) and a chemical (cypermethrin--Ammo) insecticide. Assays were conducted by incorporating the insecticides into artificial diet and by dipping cotton terminals, squares, and bolls in suspensions or solution of the insecticides. Additional studies were conducted spraying cotton terminals in a spray chamber. Concentration-mortality responses were obtained for al assay methods against all instars for Javelin and Ammo. With Elcar, concentration-mortality responses were obtained for diet only. In spray table studies, dosage-mortality responses were observed for Javelin an Ammo. At recommended rates, Javelin and Elcar generally gave 50% or less the mortality caused by Ammo.