Scientists have discovered that street lights and other forms of artificial lighting could be behind a decline in insect populations. Researchers from the UK Centre for Ecology and Hydrology conducted studies on the number of insects living near sources of white light from light-emitting diodes (LEDs). The researchers said LEDs are responsible for disrupting insect behaviour and for causing a drop in their numbers. Lead researcher Douglas Boyes said the results of his study were "eye-opening". He was surprised at the extent of the insect loss due to LEDs. He found a 47 per cent reduction in insect populations at hedgerow test sites and a 37 per cent reduction at roadside grassy areas.
Mr Boyes and his team set up LEDs at 26 roadside sites in the countryside that contained either hedges or grass verges. The researchers counted the numbers of moth caterpillars found at these sites and compared these with insects found at unlit sites. Boyes commented on the difference. He said: "We were really quite taken aback by just how stark it was." He posited that LEDs led to two drastic changes in behaviour. He said the most alarming discovery was that the lights stopped female insects laying eggs in the lit areas. Another disruption was that the lighting disturbed the feeding behaviour of the insects. The caterpillars in the unlit areas were heavier than those in the areas lit by LEDs.