This device shoots flying pests with laser beams. Overkill? Not according to Intellectual Ventures, the Seattle-based firm behind the Photonic Fence, which the company says is a more targeted weapon than pesticide. The fence creates a 30-Watt wall of near-infrared light that can identify specific species of insect. It can even tell the difference between male and female mosquitoes by analysing the way they fly. "We're looking to tell it to kill only mosquitos, fruit flies or sand flies,"…