Interaction between honeybee mandibles and propolis

Area of Science:

• Biomimetics
• Entomology
• Materials Science

Background:

• Resin deposition on woodworking tools is a persistent issue.
• The honeybee (Apis mellifera) utilizes propolis, a sticky tree resin, for hive construction and defense.
• Bees' ability to manipulate propolis suggests evolved anti-adhesive strategies.

Purpose of the Study:

• To investigate if honeybee mandibles possess anti-adhesive properties that reduce propolis adhesion.
• To understand the mechanisms behind bees' efficient handling of sticky propolis.

Main Methods:

• Anatomical study of honeybee mandibles using (cryo-)scanning electron microscopy.
• Adhesion experiments measuring propolis interaction with fresh and washed bee mandibles.
• Comparison of propolis adhesion on mandibles versus five technical materials.

Main Results:

• A scale-like pattern was observed on the inner surface of bee mandibles.
• Fresh mandibles exhibited significantly lower propolis adhesion (1 J/m²) compared to technical materials.
• Washed mandibles showed increased propolis adhesion, indicating the presence of a fluid anti-adhesive substance.

Conclusions:

• The medial surface of honeybee mandibles is coated with a fluid substance that confers anti-adhesive properties.
• This fluid coating enables bees to effectively handle sticky propolis.
• The observed surface pattern may not be the primary factor in reducing adhesion.