There's no shortage of mosquito lights on the market today that claim to repel bugs. But are they actually effective?
Mosquito-zappers typically consist of a light source to act as an attractant inside an electrical grid that electrocutes insects when they come into contact with it on their way to the light source. There may be some design variations, but the basic principle is the same for all of them.

A bug zapper doesn't work well on mosquitoes
According to a study published in the journal Nature, regular bug zappers don't kill all the insects they're designed to catch. The researchers checked six zappers and found that less than one percent of the bugs killed were biting gnats or mosquitoes.
Some types of mosquitoes aren't attracted to ultraviolet (UV) light like other insects are. That's why some UV lights don't kill mosquitoes -- the light doesn't match their wavelength.

Yellow LED lights won't attract mosquitoes
Many people think that yellow and red lights keep mosquitoes away, but research shows that they don't. These colors don't emit much UV or blue light, so they won't be attracted to them.