"The caddisflies' successful penetration into diverse aquatic habitats is largely due to the inventive use by their larva of underwater silk to build elaborate structures for protection and food gathering," the new study says.
Caddisflies fall into subgroups. Brachycentrus echo, the species Stewart studied, is one of the casemakers, which build their case and then drag it along with them underwater as they forage for food. Some caddisfly larva are retreatmakers, which build a stationary dome-shaped shelter glued to a rock, with a silk net to catch passing food.
From Sea Glue to Sticky Fly Silk
Stewart studies natural adhesives, including glue produced in intertidal ocean waters by the sandcastle worm. It has potential as glue for repairing small broken bones.
He got interested in caddisfly larva adhesive silk tape after he was contacted by a Smithsonian Institution scientist who showed him several of the tube-shaped larval cases.
"We looked inside a case through a microscope and saw these silk struts between the rocks and realized this is really interesting," he says. "So I came home and put on my fly fishing boots and started wandering mountain streams looking for caddisfly larvae."
Stewart and study co-author Ching Shuen Wang who works in Stewart's lab studied the caddisfly species B. echo from the lower Provo River about an hour south of Salt Lake City. Bioengineering undergraduate student Nick Ashton gathered the fly larvae and figured out how to keep them alive in the lab.
"There's just a fascinating diversity of these insects. Their adhesive is able to bond to a wide range of surfaces underwater: soft and hard, organic and inorganic. If we could copy this adhesive it would be
|Contact: Lee Siegel|
University of Utah