The circadian rhythm of sperm release in the codling moth, Cydia pomonella

The release of sperm bundles from testes to the vas deferens is controlled by a circadian clock in several moth species. We investigated the pattern o f sperm release in the codling moth, Cydia pomonnella L. (Lepidoptera: Tort ricidae). Sperm release in the codling moth follows a two-step rhythm in li ght-dark cycles: sperm is released from the testis before lights-off, remai ns in the vas deferens during the dark phase and is transferred to the semi nal vesicles after lights-on. This rhythm continues in constant darkness in dicating that it has a circadian nature. The release of sperm is asynchrono us in moths held in constant light. In contrast to previously investigated moths, constant light has no adverse effects on the male reproductive capac ity in the codling moth.