Besides saving you money on your power bill, it appears LED bulbs are also good for keeping insects at bay. A study by Bristol University researchers found that LED bulbs attract much fewer insects than fluorescent or filament based bulbs.
The researchers set up 18 field-test sites and there was a big contrast between the number of biting insects that were found to be attracted to the different light bulbs. The filament bulb attracted 80 percent of biting insects, versus a much lower figure of 15 percent that were attracted to the fluorescent. Regardless of whether they used LEDs with cool or warm light, these bulbs attracted a mere 2 to 3 percent of the nasty biting bugs!
The conclusion seems to be that insect get primarily attracted by the heat output of the lamp, so the more efficient it is the fewer insects you'll attract.
This was a surprising result, with lead researcher Dr Andy Wakefield pointing out that there was no different between attraction of the cool and warm light LEDs. That’s not something that was expected, as insect vision is short shifted and therefore struggles to detect longer wave, warmer light.
Why were the biting midges attracted more so to traditional light though? The suggestion is that they may have been attracted to the heat of the more inefficient bulbs, which could be seen as body heat by the insects.