University of California Berkeley Scientist Discovers Evolutionary Electrostatic Attraction Between Flies and Spider Webs (VIDEO)
ByVictor Manuel Ortega-Jimenez, a University of California (UC), Berkeley biologist, has discovered an electrically charged attraction flies have to spider webs, according to a press release on the school's website.
Ortega-Jimenez said he was playing with his daughter, who had a toy that emitted an electrostatic charge and the toy began attracting spider webs. The biologist, known for his study interest in hummingbird flight, became intrigued.
"I was playing with my daughter's magic wand, a toy that produces an electrostatic charge, and I noticed that the positive charge attracted spider webs," he said. "I then realized that if an insect is positively charged too it could perhaps attract an oppositely charged spider web to affect the capture success of the spider web."
Spider webs are usually either negatively or neutrally charged and would attract the opposite. Bees and flies produce positive charges through the friction they create by flapping their wings and, while not a substantial amount, it is enough to pull pollen off of a flower before landing.
"Electrostatic charges are everywhere, and we propose that this may have driven the evolution of specialized webs," Ortega-Jimenez, a UC Berkeley post-doctoral fellow, said.
Ortega-Jimenez tested his hypothesis by seeking out spider webs from streams in Berkley and bringing them into the lab. Next, he gathered dead insects including aphids, fruit flies, green-bottle flies and honeybees and charged them with an electrostatic generator. He then dropped the insects into a neutral web and watched the reactions.
"Using a high speed camera, you can clearly see the spider web is deforming and touching the insect before it reaches the web," he said. Insects without a charge did not do this. "You would expect that if the web is charged negatively, the attraction would increase."
After determining his hypothesis to work in a controlled environment, he said he plans to test his hypothesis to see if it works in the wild. He also hopes to find the reason behind why spiders rebuild their webs daily.