Why Petals? Naïve, but Not Experienced Bees, Preferentially Visit Flowers with Larger Visual Signals

Area of Science:

• Botany
• Ecology
• Evolutionary Biology

Background:

• Petals are showy floral structures with debated functions in attracting pollinators.
• Previous research focused on general pollinator attraction, with limited experimental testing on naive versus experienced visitors.

Purpose of the Study:

• To experimentally test the hypothesis that petals primarily attract naive, first-time flower visitors.
• To investigate the role of ray petals in pollinator attraction in Rudbeckia hirta and Helenium autumnale.

Main Methods:

• Field study manipulating ray petals on Rudbeckia hirta and Helenium autumnale inflorescences.
• Observing visitation preferences of naive and experienced honey bees and bumble bees.
• Comparing visits to intact versus petal-removed inflorescences.

Main Results:

• Naive bees were more likely to visit intact inflorescences compared to those with ray petals removed.
• By the tenth consecutive inflorescence visit, bee preference for intact flowers diminished.
• A positive correlation was found between inflorescence number and visitation of petal-less inflorescences for both bee types.

Conclusions:

• Showy petals appear crucial for attracting naive pollinators to flowers.
• Petal function may be analogous to a restaurant's large sign, drawing in first-time customers (pollinators).
• Findings suggest petals play a key role in initial pollinator recruitment.