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Insects don't swarm at LED lights

292 points • by speckx • yesterday at 7:50 PM • 139 comments • view on HN

Comments

poelzi • today at 1:46 PM

We don't see the swarms anymore, because they are all dead. If you don't look, you will not notice -https://www.science.org/content/article/germany-s-insects-ar...

AFAIK a nonprofit in Germany collected real data over the last decades. Your childhood memories of windscreens full of insects after each trip are true

tw04 • yesterday at 10:10 PM

I have LED headlights and an LED light bar on my tractor and I can say with 100% confidence that bugs swarm both. To the point I have to wear glasses to keep them out of my eyes if I’m on it for more than about 30 seconds at night.

I’m guessing he’s confusing the dramatic drop in insect life overall with a change in behavior due to different lights.

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doctoboggan • today at 1:40 PM

I think this is simply not true in my experience…

However when I visit my in laws on the Florida coast, they have “turtle lights” which are required by law to not confuse hatchlings when they first emerge from the sand. These are an orange hue and I noticed that they have way less swarming bugs than a typical street light. So I would say certain frequencies definitely confuse bugs less, but LEDs as a whole seems too broad a category to make that statement.

dghughes • today at 1:23 PM

I read an article of a former of the US biologist living for decades in Costa Rica deep in the jungle. They have a large net and each night it was blanketed with thousands if not millions of insects. Now there are almost none. Chilling.

I wonder if it's not the LED lights they just happen to exist in a time when insects have been nearly wiped out. Or it's just that area of Costa Rica.

I have a white (200W incandescent equivalent) LED light and a lot of bugs swarm it.

mahboi • yesterday at 9:18 PM

Welp, they do for mine. I've had to stop turning on outdoor LEDs because angry bees kept showing up, and there'd be 3-10 dead ones on my doorstep every morning. These are white bulbs. Might be "zombees."

Also, not sure about white bulbs, but those color-configurable spotlights definitely emit UV at least when set to anything near blue/purple. They cause certain things to glow. Probably white is doing it too but it's harder to see.

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gopalv • yesterday at 8:17 PM

My pet theory is that the dimmable LEDs repel insects (when used as a grow light).

The thing that insects can see and we don't is the rapid flashing of a PWM power controller.

I wonder if these streetlights have power saving fade-ins as the nightfall approaches instead of clicking on at sunset.

Like - https://doi.org/10.1109/CSNT51715.2021.9509652

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dylan604 • yesterday at 11:39 PM

I love to shoot long exposure timelapse of the night sky. I set up a couple of LEDs dimmed as low as possible to light a bit of the foreground (over the course of the long exposure the low light adds up so it looks normal for those not familiar). Out of sheer laziness, I just placed them on either side of my tripod. The next day after processing the shot, it was pretty much ruined because of all of the bugs showing up as tracers in each frame.

So, no, not my experience at all.

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piskov • yesterday at 10:44 PM

The entire premise (moon uv, ir etc) is wrong so the conclusion is wrong.

Sky is always brighter than the land, moon is not required.

Lamp movement is the confusion of where is “up”

https://www.nature.com/articles/s41467-024-44785-3

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legitronics • yesterday at 10:08 PM

I really don’t think UV is playing much of a role here. You could also sort their chart by power usage, or IR produced. The paper conclusion paragraph even states UV and IR as candidates but the article just says UV.

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quirkot • yesterday at 8:13 PM

I wonder how much of it is also the LED flicker. If I was a small bug and moving quickly with a high visual refresh rate, I would probably hate the experience of the LED flicker

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okanat • yesterday at 8:11 PM

Weird. My home has only LED bulbs. There are still moths and bees who get attracted to the light when I leave the window open.

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Animats • yesterday at 8:32 PM

Yes, you need some ultraviolet to attract insects. That's why bug-zappers have near UV lamps. They're usually compact fluorescent bulbs. Some ads say 365nm is the right color.

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jkahrs595 • today at 12:18 PM

I’m not even going to open this because the title is so wrong.

karim79 • yesterday at 11:15 PM

I made a huge LED display using lifx tiles (which are no longer sold). 5x5 tiles in a square, so I could hack video rendering and images to the lights. Each tile had 64 LED bulbs which could be independently controlled, both in brightness and colour.

When I did this I was in the countryside and I can state without hesitation that the insects loved it and flocked to it and while I found it cute, it was annoying because they would occasionally get trapped in the small gaps between the tiles and get stuck.

I'm therefore 100% convinced that insects just love fancy lighting setups.

joshspankit • today at 4:02 AM

They’re missing a lot of variables here.

Never minding IR and UV, not even a visible-light spectrogram of each light source

oakwhiz • yesterday at 8:17 PM

The study didn't cover high pressure sodium bulbs, the previously popular type in street lamps.

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vondur • today at 12:23 AM

The outside LED lights on my RV would disagree with this.

dddddaviddddd • today at 4:27 AM

There are some LEDs that are designed to emit UV light. They're used to attract insects. e.g. https://entoquip.com/product/entoquip-light/

krige • today at 7:23 AM

They definitely do for my LED desklight.

nxpnsv • yesterday at 9:45 PM

Wow. I put spotlight on a sheet in the garden to figure out what moths we have. Got nothing, and maybe this is why.

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HeyLaughingBoy • yesterday at 10:08 PM

Um, no. I live on a farm and often have to do chores in the dark with an LED headlight. Sometimes I have to turn it off because I'm dive bombed by so many insects.

Xcelerate • yesterday at 8:27 PM

I wonder if it’s only the UV that makes a difference. I have some Yuji SunWave bulbs (and the NIR versions). Would be interesting to test those at night against normal LED bulbs and incandescent.

theandrewbailey • yesterday at 8:54 PM

Maybe this helps answer the question of 'where did the bugs go', because windshields aren't as full of them today compared to 20-30 years ago.

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lakeviewterrace • yesterday at 10:30 PM

What lies.

I bought LED "bug lights" — those yellow bulbs that are supposed to be invisible to bugs.

Every bulb in the pack electrically failed within 10 minutes.

I gave up and went back to an incandescent. Still works perfectly.

So sick of the zero-quality LED bulbs that have entirely flooded the market. Of course they had their hand forced by government mandates, people needed mass quantities of cheap bulbs that could match a 75¢ incandescent. They didn't have this problem when LED bulbs were $20 each (and weighed about as much, due to the heat sink).

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caymanjim • today at 1:55 AM

This is utter nonsense. I live in an RV all summer. Every light is LED, inside and out. They swarm all over the lights.

ChrisMarshallNY • yesterday at 8:18 PM

I have noticed that. We have LED porch lights, and never see the usual moths and whatnot.

anthk • today at 3:39 AM

Without looking at the article, it might be IR related.

unpleasurable • yesterday at 8:19 PM

Do flames emit UV?

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skeezyboi • yesterday at 9:56 PM

because they dont emit UV.... a lot of waffle to tell me that

shmerl • today at 12:38 AM

Why can't LED lights have the same warm yellow tone? These pure white street lights are much worse than than the old style warm ones.

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speransky • today at 12:26 AM

In coastal Florida we require to use turtle-safe light fixtures, mine are 585nm and they didn't attract insects too except potato bugs

minfazhai • today at 2:44 AM

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