Brent Opell, a
professor of biological sciences in the College of Science and
a Fralin Life
Science Institute affiliate, collects a portion of a spider web.
(October, 26, 2015) A
taut tug on the line signals the arrival of dinner, and the leggy spider dashes
across the web to find a tasty squirming insect. The spider, known as an orb
weaver, must perfectly execute this moment, from a lightning-fast reaction to
an artfully spun web glistening with sticky glue.
This glue -- created when glycoproteins are secreted from a
spider’s abdomen and interact with the atmosphere -- has been studied for the
past 12 years by Brent Opell, a professor of biological sciences in the College
of Science and a Fralin Life Science Institute affiliate.
Material scientists are interested in mimicking this glue --
nature’s great adhesive -- for human products, and rely on biologists to
determine factors involved in its creation, as well as its capabilities and
limitations.
Opell’s research team, which included Sarah Stellwagen, a
2015 biological sciences doctoral graduate, and Mary Clouse of Fairfax Station,
Virginia, a senior majoring in biological sciences, recently determined that
ultraviolet rays, specifically UVB rays, are an important environmental factor
in the performance of spider glue.
They tested the webs of five local spider species -- three
that catch prey in broad daylight, and two that hunt at night or in deep forest
shade shaded areas.
Orb weaver: An orb
weaver specimen in Blackburg, Virginia.
They found that the webs of sun-soaked spiders were far more
resistant to UVB rays than the webs of those that hunt in the dark or shade,
perhaps indicating an important adaptive trait.The results were published
recently in the Journal of Experimental Biology and could inform efforts to
develop new adhesives.
"Our study adds UVB irradiation to the list of factors
known to affect the performance of spider glycoprotein glue, which includes
humidity, temperature, and strain rate," Opell said. "It is important
to more fully understand these effects as material science moves toward
producing environmentally non-toxic and energy conservative adhesives inspired
by spider thread glycoprotein."