Tongue microstructure physically constrains division of labor in bumblebee foraging

Area of Science:

• Zoology
• Ecology
• Insect Behavior

Background:

• Bumblebee (Bombus terrestris) colonies exhibit eusocial behavior with distinct queen and worker castes.
• Caste differences in hormones, metabolism, and behavior are well-documented.
• The reasons for queens ceasing foraging after worker emergence remain under-explored.

Purpose of the Study:

• To investigate the physical basis for the shift in foraging behavior observed in bumblebee queens.
• To link tongue microstructure to foraging efficiency in Bombus terrestris.

Main Methods:

• Microscopic analysis of bumblebee tongue morphology.
• Comparative study of queen and worker tongue structures.
• Assessment of foraging efficiency in relation to tongue anatomy.

Main Results:

• Significant differences in tongue microstructure were identified between bumblebee queens and workers.
• These microstructural variations correlate with differences in foraging efficiency.
• Physical evidence supports a functional explanation for the cessation of queen foraging.

Conclusions:

• Tongue microstructure plays a crucial role in the division of labor within bumblebee colonies.
• The physical morphology of the tongue explains the behavioral shift in queen foraging.
• This research offers new insights into the evolution of eusociality and caste systems in insects.