性外激素是由雄性或雌性昆虫产生的一种化学物质,其气味能激发异性产生一种或多种行为反应,这种反应直接或间接地导致交配。如松毛虫的成虫在夜晚羽化,且多在当晚交尾,它们怎样能在黑夜很短时间内找到异性?原来是雌娥释放出一种物质,并能在空气中迅速扩散,雄蛾借助触角感受到这种物质,据此找到雌蛾。该物质就叫性外激 Sexual hormones are chemicals produced by male or female insects whose scent triggers the opposite sex to produce one or more behavioral responses that directly or indirectly result in mating. Such as the pine caterpillars that become eclosion at night and often cross over the night, how can they find the opposite sex in a very short period of time? The female E releases a substance and can rapidly diffuse in the air. To this material, find the female moth accordingly. The substance is called exogenous stress