Buzz-pollinating bees deliver thoracic vibrations to flowers through periodic biting

Area of Science:

• Ecology
• Animal Behavior
• Botany

Background:

• Pollinator behavior is crucial for plant reproduction, particularly in buzz pollination where bees vibrate flowers to release pollen.
• Vibrations are transmitted through bees to flowers, with amplitude influencing pollen release, but the role of bee-flower coupling, like anther biting, is unquantified.

Purpose of the Study:

• To quantify how anther biting by bees affects flower vibration amplitude during buzz pollination.
• To investigate the role of bee biting mechanics in enhancing pollen release from buzz-pollinated flowers.

Main Methods:

• High-speed filmography was employed to record Bombus terrestris (buff-tailed bumblebee) interactions with Solanum dulcamara and Solanum rostratum.
• Flower vibration amplitudes were measured during bee visits, comparing biting and non-biting scenarios.

Main Results:

• Floral buzzing induced head vibrations up to three times greater than thoracic vibrations in bees.
• Anther vibration amplitude during biting was double that of indirect transmission without biting.
• The efficiency of vibration transmission was dependent on the angle of the bee's anther bite.

Conclusions:

• Anther biting significantly amplifies flower vibrations, enhancing pollen release efficiency in buzz pollination.
• The angle of bite influences vibration transmission, suggesting bees can modulate this mechanism.
• Diverse bee species and vibration transmission strategies contribute to varied pollen access in buzz-pollinated flowers.