Ultrastructure of the Secondary Male Genital Organ of <i>Platycnemis dealbata</i> (Zygoptera: Platycnemididae)

In this study, the secondary male genitalia of Platycnemis dealbata Selys in Selys & Hagen, 1850 was examined for the first time using Scanning Electron Microscope (SEM). The research revealed the ultrastructural features and various sensory structures of these organs. Two main types of sensilla were identified in the secondary genital organ: putative chemical sensilla and hair sensilla that detect mechanical stimuli. The study examined structures such as the ligula head, anterior and posterior hamuli, lamina anterior, and lamina batilliformes in detail. Four projections were observed on the ligula head, and it has been suggested that these projections play a role in sperm transport. Additionally, the hair sensilla on the sternum assist in detecting contact with the female and in anchoring during mating. This research compared the genital structure of P. dealbata with other Platycnemis species and revealed some similarities and differences. The study contributes to our knowledge of the reproductive biology and evolutionary adaptations of the Odonata taxon by presenting new hypotheses about the functions of these complex structures.