NEW YORK, USA/LEIPZIG, Germany: Silk spinned by caddisfly larvae underwater could one day suture surgical wounds, new reseach from the University of Utah suggests. It found that the sticky fibres used by the insects to built protective shells that keep intact in aquatic environments and do not fall appart. These chemical and structural properties could make the material valuable as an adhesive tape in medical and dental surgery.

Caddisflies, commonly known as 'rock rollers', usually live in waterbodies such as rivers, lakes and marshes. They are related to Lepidoptera, an insect order that includes moths and butterflies that spin dry silk. Caddisfly larvae also spin silk but they do so underwater in order to build an inch-long, tube-shaped case around themselves.

In the study, the reseachers examined the silk made by a caddisfly species living in the lower Provo River near Salt Lake City under laboratory conditions. They found that the fiber was made of large proteins that contain an amino acid named serine that gets 'phosphorylated' as the protein is synthesised. These phosphates are negatively charged and line up in parallel with other positive charged amino acids attracting each other making the protein water insolutable. Comparison with amino acids from three other species found great similarities, suggesting other caddisflies also use phosphorylation to spin silk underwater.

Besides the insects, these kind of adhesives could also be identified in sandcastle worms, mussels and sea cucumbers.