Macroscopy and microscropy study of the testes, seminal vesicle and mucus gland of Apis mellifera males

Abstract

Reproduction in the colony is carried out by the queen and the drones, in fact the sole purpose of the drones in life is to transfer their genes for the development of the hive. As a consequence, the sexual organs of the drones start to develop early in the larval stage and do not stop until all the spermatozoa needed for mating are produced. This results in a series of changes not only in the testes but also in the rest of the structures related to reproduction. The anatomy and physiology of the drone reproductive system has been studied for several years. However, only the normal evolution of the testes through the sexual maturation, from the larval stage to the adult stage, has been documented both macroscopically and microscopically. In this study we propose to examine several samples of testes, seminal vesicles and mucus glands from random drones of the Gran Canaria island caught during May and June 2022 to establish a relationship between macroscopic measurements and histological changes. The results of the macroscopic study allowed us to classify them in adult or young drones based on their testes size. The histology study allowed to divide the reproductive status of the drone into 4 stages, where stage I is the final phase of spermatogenesis shortly after hatching and stage IV is the complete atrophy of the testes. The combination of both studies have helped to catalogue for the first time the reproductive status of Apis mellifera drones from Gran Canaria hives. Further studies are required in order to deepen the knowledge of bee reproduction.