Sexual dimorphism in pond dragonflies like Libellula luctuosa is influenced by both male competition for territories and female mate choice. Traits like wing size, body size, and coloration have evolved differently between males and females due to sexual selection. Body size is affected by both competition for territories and mating success, while wing coloration is mainly influenced by mating success. This shows that different aspects of sexual selection can impact the evolution of distinct physical characteristics in these dragonflies.