Spider webs more effective at snaring electrically charged insects

The positive charge on an insect such as a bee or fly attracts the web, which is normally negatively or neutrally charged, increasing the chances that an insect flying by will contact and stick to the web, said UC Berkeley post-doctoral fellow Victor Manuel Ortega-Jimenez.

He also suspects that light, flexible spider silk, the kind used for making the spirals built on top of the stiffer silk that forms the spokes of a web, may have developed because it more easily deforms in the wind and the presence of electrostatic charges to aid prey capture.

Source: Here