In insects, development and phenotypic differentiation are critical for individual survival, population stability, and evolutionary diversification, with male dimorphism representing a key strategy in mating competition. Male Amantis nawai (Shiraki, 1908) exhibit pronounced wing dimorphism, comprising macropterous and micropterous morphs. Wing morphology is correlated with the number of antennal sensilla, with macropterous males possessing a higher sensilla count than micropterous males. Given that antennal sensilla serve as the primary sensory structures for detecting sex pheromones in Mantodea, male dimorphism likely reflects differences in mating behavior and reproductive investment. In this study, we investigated the timing of differentiation in these two male dimorphic traits and examined the potential regulatory role of juvenile hormone (JH). By tracking exuviae at each molt, we compared wing pad and antennal morphology crossing developmental stages. Significant divergence in wing pad morphology was detected as early as the third instar, whereas differences in antennal sensilla number emerged only at the adult stage. JH has been implicated in regulating wing polymorphisms and sensory organ development in other insects, with higher JH titers usually associated with micropterous wings. Therefore, we tested whether wing and antennal morphologies could be modulated by applying a JH analog (methoprene) to macropterous males and a JH inhibitor (DZNep, 3-deazaneplanocin A) to micropterous males. Treatment with methoprene in last instar males significantly reduced both wing area and the number of antennal sensilla, whereas DZNep treatment had no observable effect on wing or antennal morphology. These results suggest a potential role for JH in regulating wing and antennal differentiation in mantids, although further investigation is needed to determine the effects of JH at specific time points within each instar.