Street lights could be causing a decline in insect numbers. Researchers in the UK carried out studies on the number of insects living near white light from LEDs. The researchers said the LEDs are affected insect behaviour. The lead researcher said he was surprised at how much LEDs affected insects. He found a 47 per cent reduction in insects near lit hedgerow test sites and a 37 per cent reduction near lit roadside grassy areas.
Researchers set up LEDs at 26 roadside sites that contained hedges or grassy areas. They counted the number of caterpillars at these sites and compared this with insects found at unlit sites. A researcher said the difference was "stark". He said the lights stopped female insects laying eggs in the lit areas. In addition, artificial lighting disturbed what insects ate, so the caterpillars in the unlit areas were heavier.