Study: LED lights draw fewer insects

BRISTOL, England, Nov. 15 (UPI) -- A porch light and a crack in the screen door can make for an itchy evening. Lights are known to attract insects; some harmless, like moths, others bothersome, like biting midges. But not all lights are equally attractive.

Researchers at the University of Bristol found LED lights attract fewer insects than traditional filament lamps. They published their findings in the journal Ecology and Evolution.

Scientists set up LEDs, traditional incandescent lamps and compact fluorescent lamps at 18 field test sites in England. More than 4,000 insects were captured and identified during the testing. Test results showed traditional incandescent lamps attract four times as many insects as LEDs.

Approximately 80 percent of all biting flies visiting the test sites congregated around traditional incandescent lamps. Just 2 to 3 percent visited LEDs.

"We were surprised by the number of biting flies drawn to the traditional tungsten lights," lead researcher Andy Wakefield said in a news release. "We do not know why this is but we know that some insects use thermal cues to find warm-blooded hosts in the night, so perhaps they were attracted to the heat given off by the filament bulb."

Researchers say more work needs to be done to analyze the effects of different lights on heat-seeking flies and mosquitoes, species which transmit disease.