Stingless bees tongue morphology is different compared to honeybees

Abstract

Stingless bee species including Geniotrigona thoracica, Heterotrigona itama, and Tetragonula laeviceps are cultivated domestically in Malaysia to produce honey and bee bread and to encourage plant pollination. Bees use their mouthparts to extract nectar from diverse flowers. Different bee species are attracted to the nectar of these flowers, which is produced in varying concentrations. Understanding the morphology of the mouthparts in various stingless bee species is crucial for comprehending their robust foraging behaviour, a subject currently little explored. This study aimed to examine the detailed structure of G. thoracica, H. itama, and T. laeviceps mouthparts, with a focus on the tongue (glossa) structure. Our findings revealed that each of these three stingless bee species possesses a distinct flabellum geometry. Furthermore, we demonstrated that, in contrast to honeybees, each sensilla on the stingless bees’ flabellum is composed of a single sensilla strand. Owing to this distinction, we discuss the potential difference in nectar extraction efficiency between honeybees and stingless bees. A comprehensive understanding of bees’ mouthparts contributes to the conservation of plants and bees by optimising pollination efficiency, supporting plant reproduction, encouraging habitat conservation, and guiding native plant restoration efforts. By protecting these crucial interactions, we can safeguard ecosystems and ensure the continued survival of these invaluable pollinators and the plants they rely on.