Honeybee Tongue Hairs are Stiff and Hydrophobic
By Science
News Staff / Source
Wei et al. found that honeybee tongue hairs’ hydrophobicity can prevent the hairs from being adhered to the soft tongue surface, which could significantly enhance the deformability of the tongue when honeybees feed at various surfaces and promote their adaptability to different environments. Image credit: Jiangkun Wei.
The
honeybee tongue, foraging liquid food in nature, has a unique segmented surface
covered with dense hairs. Since honeybees are capable of using their tongue to
adapt to possibly the broadest range of feeding environments to exploit every possible
source of liquids, the surface properties of the tongue, especially the
covering hairs, would likely represent an evolutionary optimization.
A new study by researchers from China and Germany shows that honeybee tongue hairs are stiff and hydrophobic, the latter of which is highly unexpected as the structure is designed for liquid capturing.
A
honeybee can feast on flower nectar, sap, fruit juice or salt water.
The
bee tongue consists of a series of ring-like segments, each bristling with 16
to 20 hairs.
It
must be able to interact with a broad spectrum of surfaces, such as narrow
flower openings, coarse tree bark, irregularly shaped rotten fruit and damp
soil.
The
bee’s success in exploiting these very different resources depends on the
surface properties and deformability of its tongue.
Scientists
had previously studied the structure and motion of the hairs, but their surface
properties and relationship to overall flexibility hadn’t received the same
scrutiny.
In
the new study, Sun Yat-Sen University researcher Jianing Wu and colleagues used
various forms of microscopy, along with high-speed videography and
computational modeling, to study honeybee tongue hairs.
These
techniques showed that the individual hairs are stiff and hydrophobic, unlike
the ring segments, which are soft and hydrophilic.
This
difference prevents the hairs from sticking to and stiffening the tongue once
it starts bending, so it can bend further to get into crevices and reach food.
The
stiffness of the hairs also enhances their durability, enabling the bee to use
its tongue millions of times during its lifetime.
“Our
findings could inspire the design of sophisticated new materials, such as
flexible microstructured fiber systems to capture and transport viscous
liquids,” the authors said.
The study appears in the journal ACS Applied Materials & Interfaces.
Jiangkun Wei et al. Enhanced Flexibility of the
Segmented Honey Bee Tongue with Hydrophobic Tongue Hairs. ACS Appl.
Mater. Interfaces, published online March 8, 2022; doi:
10.1021/acsami.2c00431