Extended lifespan and parent–offspring mating through intermediate care of refrigerated silkworm moths

抄録

 Silkworm moths (Bombyx mori) typically survive for around 1 week without feeding, making parent–offspring mating impractical because males usually die before the next generation emerges. Although artificial insemination using cryopreserved sperm has been developed to address this limitation, it requires specialized equipment and technical expertise.

 In this study, we applied intermediate care, a method originally used for long-term storage of diapause eggs, to refrigerated adult male moths. Male moths were maintained at 5°C and exposed to 25°C for 3 h once a week. Survival and mating capacity were assessed after prolonged storage. All moths in the control group died within 8 weeks, whereas several individuals subjected to intermediate care survived for up to 8 weeks. Among these survivors, most exhibited mating behavior, and some successfully copulated with females. Notably, one male mated with a female from the subsequent generation and produced fertilized eggs, demonstrating parent–offspring mating.

 These findings indicate that intermediate care can extend the lifespan of adult silkworm moths under simple conditions and enable parent–offspring mating. This study provides the first evidence that lifespan extension in adult moths permits parent–offspring mating without reliance on artificial insemination or cryopreservation techniques.