Abstract: By using both routine anatomy and paraffin-section microscopy, the morphology and histology of internal reproductive organs and external reproductive organs of the male adults in Ectropis obliqua Prout were described. Like other major organizational structure in Lepidoptera, the external organs including harpes, tegument, uncus and aedeagus, the internal organs consisted of a testis, a pair of seminal vesicle, a pair of accessory glands, and ductus ejaculatorius simplex. Eight radial testicutar tubule which were separated by thinner connective tissue were also observed in testis slices. And internal thinner connective tissue distributed a large number of spermatogonia, spermatocytes and mature sperm bundles. The results found seminal vesicles and vas deferens were filled with liquid and also showed a large quality of sperm bundles in the seminal vesicles. This is the first study to clarify the male reproductive system and sperm bundles filling state in the thinner connective tissue of this species and it provides more guiding significance for field forecast, phylogeny and species identification.

Key words: Ectropis obliqua Prout, male adult, reproductive organs, morphology, ultrastructure