|Description:||Under the moderate magnification of 207x, this scanning electron microscopic (SEM) image revealed the rear leg anatomy of a carpenter bee, Xylocopa virginica, at the region of the "tibial spur". These spurs, which are exoskeletal protuberances, enable the bee to grasp various floral structures, thereby, enhancing its maneuverability inside the flower while it obtains it nectar meal, and pollinates the plant. See PHIL #8828 for a view of the same tibial spur under a lower magnification.|
The rear leg tibiae in male Xylocopa virginica, are adorned with only one spur, while female bees display two spurs per tibia. The leg spurs also directly facilitate the pollination process. When they are used to grasp floral structures such as the filaments, which are attached to the pollen-producing anthers, they move up and over these structures, thereby, scraping pollen off of these structures, and dispersing it throughout the flower, or on to the bee directly. Note the comb of modified scales, which act to improve the spur's ability to collect, and redistribute pollen during the nectar retrieval, and pollination process.