To determine an optimal sex pheromone blend for attractingHeliothis virescens(F.), field studies were conducted using pheromone-baited cone traps. Tests with various combinations of the seven components found in sex pheromone glands indicated that a blend of (Z)-11-hexadecenal, (Z)-9-tetradecenal, hexadecanal, and (Z)-11-hexadecenal dispensed to rubber septa at a ratio of 65.1:1.6:32.6:0.7 was optimal. Blends containing no (Z)-11-hexadecenol, or those with levels greater than 1% relative to (Z)-11-hexadecenal, were generally found to be suboptimal.