The biogenic amine, octopamine, has been proposed as the transmitter in the firefly light organ (Evans, 1980; Robertson, 1981). Whereas initial studies implicated adrenaline (Smalley, 1965; Carlson, 1968a), octopamine was found to be more potent in inducing luminescence than any amine other than synephrine (Carlson, 19686). Octopamine, but not synephrine, was found in adult lantern segments (Ro...