Does red light have negative effect on fireflies?

Hi there,

I’d like to observe fireflies in the natural habitat and make some photographs. I have a problem with moving through the forest in the night.
I read that fireflies a strongly affected by the light pollution, therefore I think it would be unethical to take a bright headtorch to hang around night forest. At the same time, walking in the forest in complete darkness is inconvenient and dangerous.
I heard that red light is not so severe light pollutant, therefore I wondering is it also less harmful for the fireflies?

Good question. Light will generally always have a negative impact on fireflies, though red light is likely to have less impact than other colors. This is a decent write up for fireflies with the caveat that there are many species and responses will likely vary somewhat:

That said, if you are taking a fairly low intensity red light out for an occasional trip, this isn’t likely to have a serious negative impact. The main worry here is always on light sources over many nights that are very strong which could essentially eliminate firefly mating in a given area. So if you keep your lighting low power, red, and are moving to different areas/not keeping it on all the time, I think you’ll be fine to do some nocturnal observations!


Red light would likely less hinder your dark adaptation versus other choices. If your dark adaptation is less hindered you may need a less intense light. Of course, dark adaptation is time consuming, and full dark adaptation takes about 30 minutes, although you get a good chunk of it in the first five minutes.


This question reminded me of a very strange nature experience I had in Ecuador. I was watching the fireflies – yellow-green lights flashing – and then there was one red light, flashing more slowly but moving much more quickly, so that it crossed the whole field in three seconds, and flashed the same number of times. I thought, was that a firefly too? And why just the one? I have never seen anything like that anywhere else.

Well I think this can help


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