Adult vial bioassays were used to determine toxicity of selected insecticides to brown, Euschistus servus (Say) and southern green, Nezara viridula (L.), stink bugs captured in blacklight traps in the Brazos River Valley of Texas. Toxicity of cypermethrin, lambda- and gamma-cyhalothrin, and chlorpyriphos were compared for the 2 species. Regardless of insecticide, LC50s of these insecticides were significantly higher by 2 to 26 times for brown than southern green stink bugs. Results of these studies are discussed relative to insecticidal control of stink bugs on cotton.