Spider Webs React to Electrically Charged Insects, Increasing Capture Chances [VIDEO]

Insects such as a bees or flies can acquire a positive electric charge while in-flight, which makes them more susceptible to becoming ensnared in a spider web by a force of attraction created by the web's own negative or neutral charge, according to a new study.

Victor Manuel Ortega-Jimenez, a post-doctoral research fellow at the University of California, Berkley, told The Daily Telegraph that insects can acquire a positive electric charge by flying through an airstream of charged particles or walking over a charged surface. The charge insects pick up is small compared to the volts a human would pick up walking across a rug, but its enough so that bees, for instance, can draw pollen off a flower before landing.

He also suspects that a special type of lighter spider silk used on top of the stiffer silk that forms the spokes of a spider web was evolved because it can more easily deform the wind and alter electrostatic charges to aid prey capture.

"Electrostatic charges are everywhere, and we propose that this may have driven the evolution of specialized webs," Ortega-Jimenez said in a statement.

Ortega-Jimenez said he became clued in to the idea when he was playing with one of his daughter's toys, a wand that produces an electrostatic charge.

"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."

He set up an experiment in the lab to test his theory. By taking a variety of dead insects such as aphids, honey bees and fruit flies and using an electrostatic generator to charge the insects, Ortega-Jimenez found that the webs of cross-spiders (Araneus diadematus) deformed when the charged insects were dropped onto the neutral, grounded webs.

The charged insects caused the web to move several millimeters as they passed by, enough of a change to mean the difference between life and death for a passing insect. Insects without a charge did not cause the web to move.

"Using a high speed camera, you can clearly see the spider web is deforming and touching the insect before it reaches the web," Ortega-Jimenez said. "You would expect that if the web is charged negatively, the attraction would increase."

Ortega-Jimenez plans to conduct further research on electrostatically charged insects and spider webs, including whether what he found in the to be true in the lab is also at play in the wild. Click here to see a video of the web reacting to a charged insect. 

The research was published in the journal Scientific Reports.