Mouthpart separation does not impede butterfly feeding.

Area of Science:

• Entomology
• Fluid Dynamics
• Plant-Insect Interactions

Background:

• Butterfly proboscis (mouthpart) function is vital for nectar feeding and pollination.
• Feeding is traditionally thought to rely on a sucking pump and sealed tubular structure.
• Capillarity and wettability dynamics are also critical for fluid uptake from surfaces.

Purpose of the Study:

• To investigate if butterfly proboscis functionality is maintained after experimental splitting.
• To test the hypothesis that proboscis integrity is not essential for feeding.
• To assess the role of capillarity and wettability in damaged proboscides.

Main Methods:

• Experimentally splitting the proboscides of eastern black swallowtail and cabbage butterflies.
• Splitting occurred in the drinking region or mid-proboscis 24 hours before feeding.
• Butterflies were fed a red food-coloring solution to assess fluid uptake.

Main Results:

• Approximately 67% of split proboscides reassembled.
• All butterflies with reassembled proboscides showed functional feeding.
• Butterflies with un-reassembled, split proboscides also demonstrated fluid uptake capabilities.

Conclusions:

• Butterfly proboscis functionality can be retained even when the structure is compromised.
• Capillarity and wettability dynamics contribute significantly to fluid uptake.
• Wild butterflies may possess fluid uptake capabilities despite partial proboscis injury, impacting pollination ecology.