How to cheat when you cannot lie? Deceit pollination in Begonia gracilis

Area of Science:

• Plant-pollinator interactions
• Evolutionary ecology
• Floral mimicry

Background:

• Pollinator deception through floral mimicry is a known evolutionary strategy.
• Exploitation of pollinator sensory biases is proposed but lacks extensive field evidence.
• Begonia gracilis exhibits intersexual mimicry with exposed rewarding structures.

Purpose of the Study:

• Investigate the mechanism of deceit pollination in Begonia gracilis.
• Test the role of mimicry and sensory bias exploitation in reproductive success.
• Determine how flower morphology influences pollinator foraging decisions.

Main Methods:

• Observational studies of Begonia gracilis pollination.
• Analysis of pollinator visitation rates to male and female flowers.
• Assessment of fruit set in relation to floral traits.
• Artificial manipulation experiments to validate findings.

Main Results:

• Pollinator perception of reward in male flowers is affected by androecium and perianth size.
• Pollinators preferred male flowers with large rewards and small perianths.
• Non-rewarding female flowers mimic the deceit strategy of male flowers.
• Artificial flower manipulations confirmed natural observations.

Conclusions:

• Begonia gracilis employs intersexual mimicry, exploiting pollinator sensory biases.
• Relative size of floral parts is crucial for pollinator foraging decisions.
• Continuous variation in perianth and reproductive organ size may be adaptive.