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Why flying insects gather at artificial light

nature.com

91–100 of 183 posts

Re: Why flying insects gather at artificial light

#91

How is it compatible with the times of the day/year when the sun is absolutely not "up there" but closer to the horizon?

The insects still orient themselves towards the sky, as it's the brighter hemisphere. They're not locking directly onto light sources, just using them as a cue for orientation. But that fails when the reference point is not distant, as with an artificial light.

Re: Why flying insects gather at artificial light

#92
post #89

Earlier quoted context omitted.

You're likely describing citizen science and engineering, which cannot really be considered for publication in Nature. The work here represents many thousands if not millions of hours of accumulated scientific skill in building experiments that are likely to produce useful conclusions, rather than falsely rejecting the null hypothesis. I've worked in citizen science and I have even done some exciting stuff in my gara…

> You're likely describing citizen science and engineering That's what you are describing. If you read my comments, I am not talking about that (though I don't object to it), and my main point is that science is not defined by the type of work that gets published in journals, or by whatever qualifies as 'citizen science'.

I read all your comments carefully, in detail, before responding. Can you give us some examples of what you mean? I'm struggling to see how somebody on their own could come up with a non-trivial scientific result that was meaningful in any way.

Re: Why flying insects gather at artificial light

#93
post #80
post #70

What about the color? I know it is slightly orthogonal, but the article says: "This is true even at night, especially at short wavelengths ( I always wondered: isn't there a light color that we human see and that minimizes the impact on the insects? Say if we only used red light in the cities, would it help?

My parents used to use these. I don’t recall if they worked, and I’ve not seen them in quite some time. https://www.lightbulbs.com/blog/how-do-bug-lights-work

Camping lanterns are still sold with this idea. For instance, I have one of these: https://hardkorr.com/au/product/u-lite-dual-colour-led-lante...

> The wavelength of our orange LEDs is 610nm, putting them outside of the spectrum visible to must bugs, but still well inside the boundaries of human vision. As a result, most bugs will not congregate around our orange light because they simply don’t know it is there.

That colour also feels reminiscent of a camp fire, which I've often thought could be related — a bug wouldn't survive long if it flew into fires.

Re: Why flying insects gather at artificial light

#94
post #37

Earlier quoted context omitted.

That’s my understanding too. The way I thought about this before was that normally an insect would ‘keep the moon’ on one side to navigate straight, but artificial light messes that up and they end up spiraling around those light sources. Which seems exactly the behavior that they have demonstrated in the research.

> they end up spiraling around those light sources What I'm struggling to understand is how the insects then reach so close to the artificial light. Why don't they spiral the artificial light from a great distance like 1 metre or 2 metres away? I see the insects hovering like millimetres or centimetres away from artificial light.

If I understand correctly part of the explanation is that when they're flying horizontally they need to compensate for gravity by pushing up, kind of like what planes do. If you put them in a place where there's no gravity with a light floating in the middle of a room they'd orbit the light while also getting closer as they're trying to compensate for gravity, and when you put gravity back I guess that produces the weird orbiting we observe.

Haven't seen flying insects since last summer but if I think they kind of lose altitude the closer they get to the light source, which would be when their torso is less horizontally oriented.

Also this is just a guess but I imagine the closer they're to the light source and the larger the contrast between bright and dark is, the stronger is their tendency to get locked into the orbiting path as opposed to flying randomly.

Re: Why flying insects gather at artificial light

#95
post #9

I had a really weird observation. Do you know how in the summer flies tend to enter rooms and circle the middle of it (where usually the turned off light fixture is)? And they seemingly can't or don't want to find open window to leave the room? At one point for unrelated reasons I replaced light fixture in my room with more than 200W worth of strongest E27 Philips LED lightbulbs I could find (20*1521lumen). Few flies…

I have a few theories, these are my own speculations, so I could be wrong.

I speculate that the flies rely on a phenomenon called "optic flow" for navigating around obstacles. Basically the rate of feature movement perceived on each side of their head/compound eyes determines proximity to objects. Their vision is very blurred, so features need to be quite large, or at least contrasting. If you have a dimly lit room, with white walls, the whole space will appear mostly featureless to the fly, until they get close enough to the wall, and thus fly around in circles.

Perhaps they also use a fixed contrasting object as a reference point, like the light fixture (turned off) and return to it if they veer off too far into the "featureless void". If you turn on the light, the perceived illumination in the space is inverted. The light makes previously invisible objects around the room more contrasting for them to navigate about and to fly closer, even land.

Re: Why flying insects gather at artificial light

#96
post #92

Earlier quoted context omitted.

> You're likely describing citizen science and engineering That's what you are describing. If you read my comments, I am not talking about that (though I don't object to it), and my main point is that science is not defined by the type of work that gets published in journals, or by whatever qualifies as 'citizen science'.

I read all your comments carefully, in detail, before responding. Can you give us some examples of what you mean? I'm struggling to see how somebody on their own could come up with a non-trivial scientific result that was meaningful in any way.

I believe the point he's trying to make is that he still considers it be science, regardless of the label you've chosen to place on it.

Re: Why flying insects gather at artificial light

#97
post #9

I had a really weird observation. Do you know how in the summer flies tend to enter rooms and circle the middle of it (where usually the turned off light fixture is)? And they seemingly can't or don't want to find open window to leave the room? At one point for unrelated reasons I replaced light fixture in my room with more than 200W worth of strongest E27 Philips LED lightbulbs I could find (20*1521lumen). Few flies…

I’m curious: how are those 20 bulbs installed? You got a single fixture with 20 bulbs??

Re: Why flying insects gather at artificial light

#98
ive seen all types of flying animals fly to a light source, and ive observed a family of lizards feed upon the bug who are attracted to the lamp. the parents taught the baby lizards who now are teenagers. once a big grasshopper flew into the light and passed out and a lizard saw it happen but didnt go down and eat it. lights are on at night and cold nights lizards are dumber and lazier than usual.

Re: Why flying insects gather at artificial light

#99
post #92

Earlier quoted context omitted.

> You're likely describing citizen science and engineering That's what you are describing. If you read my comments, I am not talking about that (though I don't object to it), and my main point is that science is not defined by the type of work that gets published in journals, or by whatever qualifies as 'citizen science'.

I read all your comments carefully, in detail, before responding. Can you give us some examples of what you mean? I'm struggling to see how somebody on their own could come up with a non-trivial scientific result that was meaningful in any way.

> a non-trivial scientific result that was meaningful in any way

I assume you mean non-trivial and meaningful to society and to the progress of human knowledge. My whole point is that those properties are not necessary to doing 'science'.

What I do is non-trivial and meaningful to me and sometimes to people I know, to a few people on the Internet, and/or to my community or co-workers. Though sometimes the data is trivial even to me, and still it's a joy, the joy of exploration and curiosity. Also, there are infinite questions beneath the threshold of professional science costs that can be investigated (and some of those are just hyper-local questions).

Science doesn't have to be big and globally meaningful. That stuff is very important, but that's not all there is - not nearly. Just do science - just do it and stop debating if and the semantics - do some experimentation, with some hacked objectivity, controls, etc. It's a powerful tool: what you discover when you actually try it, whatever it is, will change your perspective, will raise new questions, and will lift up your mind and spirits, guaranteed. I know so much more about the world than many people, simply by doing a bit of exploration through experimentation.

Re: Why flying insects gather at artificial light

#100
post #9

I had a really weird observation. Do you know how in the summer flies tend to enter rooms and circle the middle of it (where usually the turned off light fixture is)? And they seemingly can't or don't want to find open window to leave the room? At one point for unrelated reasons I replaced light fixture in my room with more than 200W worth of strongest E27 Philips LED lightbulbs I could find (20*1521lumen). Few flies…

I’m curious: how are those 20 bulbs installed? You got a single fixture with 20 bulbs??

Fixture adapter like this maybe? https://a.co/d/iOgDKZf
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