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.
I second this. When my home was infested by flies (I stopped counting at ~1000 over a 3 week period) they would always swarm and hang out by my grow lights (full spectrum LEDs) in my kitchen window. It was a great place for fly traps on the flip side.
It is quite possible that flies prefer one part of the light spectrum more than another part, but to say in the title that they don’t swarm at LEDs is misleading at best.
Also the light bulbs have excellent performance at "catching" bugs because they land on hot stuff and die. I had some GU-12 ceiling halogen lights in my previous apartment and the rims were always covered by bugs that decided to land there and as they were hot from halogens, boom, bug destruction machine
Insects are attracted to low wavelength light, which includes both UV and blue light. Cool color LEDs are usually blue LEDs, and are often used for headlights/etc because they get higher lumen ratings for the power used. Headlights/lightbars are also really bright compared to porch lights.
If you compare an incandescent soft white porch light to a similar brightness soft white led light, you will probably see dramatically more insects at the incandescent bulb.
.
> We found that LEDs attracted significantly fewer insects than other light sources, but found no significant difference in attraction between the “cool” and “warm white” LEDs.
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.
The color configurable bulbs or the high CRI bulbs typically use a 400nm led source and some do use a 380nm but those are much rarer and expensive. Also almost any amount of plastic or glass will significantly absorb that wavelength of UV.
I have a 405nm laser pointer and it makes certain things (any% titanium dioxide) absurdly bright from fluorescence. So you probably aren’t getting UV from those bulbs, but certainly some IR.
PWM drivers should be banned, the quality of lighting is horrendous and it murders LEDs. You have an rms currernt that is in spec but the peak is way too high.
anecdote: I work in a factory, we have thousands of light fixtures. The older constant current LED fixtures have lasted a decade, the new PWM driven lights have had a ~1% failure rate.
How do you know the difference? Constant current is almost certainly a PWM controlled buck/boost regulator. The flicker is attenuated by inductance, more or less depending on the design.
Use a fidget spinner to see the difference. Spin up a 3 lobe fidget spinner and catch the reflection of the LED on it's surface. As the speed changes, a flickering LED will freeze the motion of the spinner. Even more fun with spinners :-).
Yes, adding an inductor will fix the problem, but that costs money. Not enough customers are complaining about the light flicker to justify the higher price.
I guess the distinction is 'filtered' vs 'unfiltered' then. If you look at the lights that fail early using a high framerate camera (1k fps) they flicker between full brightness and fully off. The lights that last longer have some ripple but its 5-10% brightness.
One of my favorite things I read growing up was a passage about what it's like to be a fly watching TV.
In those days TV's were big CRT boxes, illuminated by the electron beam which would race across the screen row by row.
A housefly's "refresh rate" on its eyeballs is much higher than that of a human, so the fly wouldn't see an image as we do, but would presumably find it quite relaxing watching the dot of light slowly move across the screen.
The streetlights in my neighborhood still have the round photo sensors on top, that have something like a watt of standby current for the sensor itself. I don't think they're trying hard to save powwer.
The ones that have a watt of standby are the really old models (probably not sold for the last 30yrs) where you'd have an LDR controlled relay with no electronics
Anything more modern than that, even if it has a similar case, will use less power
A low-voltage photocell uses like 5mA @ 24VAC these days, it’s nowhere near a watt. You can buy a wireless battery powered photocell or occupancy sensor that will last a decade.
The article bluntly states: "Moonlight contains ultraviolet (UV) and infrared wavelengths because it is merely reflected sunlight. Insects cue on UV, believing it to be the moon. . . . Incandescent lights transmit UV but LEDs do not. Insects are far less attracted to LED."
However, my mind developed a similar conjecture to your's: what if the common frequencies of PWM occur within a kinetic visual blindspot of insect vision, like human saccades [0] in the novel Blindsight [1], so that insects are not aware of the LED at all?
They've had many generations to evolve alongside all human false light sources. Insect generations are usually pretty short. Perhaps they just find it evolutionary useful to cluster around human sources of light. Presence of human food, liklihood of bumping into other insects of the same species, warmth, etc.
If human sources of light were interfering somehow, they've had hundreds or thousands of generations to breed out that proclivity.
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.
Bugs don’t just materialize out of the ether to swarm lights. Not to feed swallows. They are there and you will encounter them if the density is much more than zero.
There are bugs. You photographed bugs. Maybe more than you would have without lights at all, maybe about the same.
Also better lights don’t necessarily mean perfect lights. We do lots of things to reduce harm. Unfortunately sometimes we do them too much and conserve a significant fraction of the original harm by increasing demand.
I often visit a place full of swallows and mosquitoes. The swallows eat mosquitoes, and the mosquitoes eat me. So when I get bit, I joke I'm feeding the birds.
I was afraid I'd get a "pics or didn't happen" request! Even though that's not that's why you're asking. I don't know that I have the footage any more. I wasn't happy with it, and that was many many moons ago. It's not something I would have spent a lot of effort making copies of.
Could have keyed your external camera flash to a relay driver for the lights. Blinking them on for 1 second every 5 minutes shouldn't get gross moth dust on everything.
Also different insects are blind to various areas of the spectrum LED lights cover. So you just get different creatures showing up.
An incandescent filament bulb will probably give you warmer color in the deeper reds. Too high of a color temperature at night makes things look odd, and you may not immediately notice the HDR capture is skewed.
The neutral "Bright White" Philips A19 Ultra Definition Frosted Dimmable LED Bulbs are about as good as you can get with cheap retail consumer E26 bulbs. Still, the weaker reds may to be an issue depending on what you are capturing, and one may have to drop to a lower color-temperature indoor version like "Soft White". =3
I've experimented with this, but for single images exposing a person at shutter open, and then letting the person leave frame while continuing to expose the sky.
Having a strobe every exposure during a timelapse is annoying though. You'd get run out on a rail at a star party with nonsense like that. Sometimes, it really helps to think about others when doing your own thing and not being an asshat just because you want to do something
> Sky is always brighter than the land, moon is not required.
Speaking of things being wrong...how can you come to this conclusion? There are many beaches where turtle hatchlings get confused by all of the lights on land where they crawl away from the ocean instead of towards it. Land is so bright, that the vast majority of humans can no longer see the night sky. So again I ask, how do you come to the conclusion that land is darker than the sky?
If P then Q, P therefore Q. Q is not the conclusion, it's just the consequent. If P is false, then Q could be true, but claiming Q is true because P is true when P is actually false is a wrong conclusion.
take something you know to be true. now come up with a stupid, falacious argument for it. now you can see that seeing an argument is bad doesn't mean the conclusion is wrong.
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.
I think it’s to do with the LED flicker. You can sometimes see it in your peripheral vision (ie your light/dark receptors) but your RGB cones aren’t as good at spotting it.
Insects eyes are biologically very different.
With LED lighting, if you have lots of spot lights in the ceiling and and open door, you’ll likely find that the light leaving the house is a bath of reflection from different sources inside the house and that likely cancels out the worst of the flicker.
Probably but is it too much to expect something like reading the article before commenting? We all know that many articles/blog posts titles on the internet are clickbait.
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.
Can confirm my spiders like cozy heat. I often get them chilling directly above my computer station, legs spread out like a pancake. Presumably there's a warm air current hitting the ceiling. It might also be the light though.
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
There are odd visual illusions though, like humans perceive the Wagon-Wheel Effect even though there's no obvious reason it should happen. This is the effect where the speed of a rotating object varies depending on its sync with a discrete exposure period.
You mention it yourself, these illusions only occur with "discrete exposure periods". This is moreso related to video recordings and less about how the eye sees actual physical objects. Such illusions do NOT occur with natural light.
Edit; to be clear there is a version of the wagon wheel effect under natural light, I'm just saying that the main one with discrete exposure periods does not occur irl
> You mention it yourself, these illusions only occur with "discrete exposure periods".
Have a look at https://www.pnas.org/doi/epdf/10.1073/pnas.93.8.3693; my point was that there is documented research that says even with continuous illumination and an (apparently) continuous camera (the brain), this happens:
> The illusion of wheels or other radial patterns rotating back-
ward in continuous light, together with the perception of
supernumerary spokes, suggests that the human visual system
processes sequential episodes of information rather than a
continuous temporal flow. In addition to accounting for this
remarkable illusion, a strategy of vision that parses the world
in this way can explain why movies are so realistic (simply
because that is the way we normally see things) and how we
detect motion (by comparing the position of the same objects
in sequential episodes).
I'm confused. I thought seeing/measuring lower frequencies due to a low sampling frequency, where the lower perceived frequency is basically the modulus of the real frequency and the sampling rate, is a well-known phenomenon independent of the actual sensor implementation.
I highly recommend the pop science book An Immense World by Ed Yong to disabuse you of this notion. There is a sort of refresh rate (not exactly the same but good metaphor) for everything at every level of living being we study. It gives enough information for you to read the actual studied should you have more questions after reading it.
Try walking outside in a clear night. Look up, notice some stars, or aircraft lights. Now rotate in place, and see how low your vision's FPS is in the dark: the rotation will be visibility jumpy.
An insect, with its much simpler visual processing, and facing a bright light, will likely achieve a much higher FPS, sufficient for the sub-kilohertz flicker to be very visible.
For a game i tried to model the behavior of our eyes in the dark and read up on a lot of that stuff. Not once was there a suggestion of jumpy vision. And that is also not my experience. In low light things begin to smudge, lots of ghosting the further in the periphery of your view they move in.
Yeah, i know that's how the physics works, but effectively my computer monitor doesn't flicker for me but a strobe light does. Whatever the proper term for that is what I'm talking aobut
But there is a neurological component in "optical processing" that can be modeled as a discrete rate of update although the underlying physiology is still being investigated.
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.
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.
I wonder what percentage is pesticides vs development? I currently live in an area(US) where a drive to the nearest city of size absolutely coats my car in bugs. US, mostly farmland(soybeans/corn). I wasn't here 30 years ago so can't say there's as many as then, likely not. But if it were only pesticides I'd expect the rural areas to have less bugs than the more developed areas...
As someone who has made many interstate trips through Australia's farmland, I can say that over the decades there's definitely been a drop in windshield splatter. It's unsurprising that pesticide deployed at scale reduces bug populations. Even herbicides which aren't intended as insecticides have limited product advantage to being bug-safe (apart from pollinated crops... and even then). Some aren't even human-safe. An extreme example is paraquat, that while being a herbicide, is irreversibly deadly to humans^ when consumed even in tiny amounts.
I would lean towards the urbanization of the land as well. I rarely get bugs on my car in the city, but as soon as I head out to the country at night my car is covered. I had to stop at a gas station back in May not for gas but just to squeegee the windscreen so I could see again.
wow this would be a neat twist if true - we all defaulted to the negative explanation of having killed them all where a much more positive explanation might be that we're no longer luring them to their deaths at the leading edge of automobiles?
I guess it is most likely some combination of the above, but if there's any evidence it would be a neat reframing
I think they just all collectively got tired of hearing my dad's punny about "it doesn't have the guts to do that again" any time a bug squashed on the windscreen.
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.
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).
It was always a scam because LED bulbs need power supply and that creates heat, switching hundreds of volts ac to low volt dc. They don't last any longer than incandescent in fact they have much shorter lifetimes.
Average lifetime of my Philips bulbs is ~ 8 months before they develop the 'flicker of death'... at roughly $7/bulb I might as well go back to black market incandescents.
A cheaply made bulb doesn't really support your theory though. Before LEDs, the anti-bug yellow incandescent bulb was available. It puts of a horrendous light and most people didn't like them. It's in the top 3 of lights that I do not like: 1) anything CFL, 2) any cool white (>3600K) light at night, 3) ugly yellow anti-bug light, 4) whatever the ugly greenish light 7-11 uses at some gas stations, 5) 4300K fluoro tubes.
IIR, hydrogen flames can emit enough of their energy in the UV for that to be a serious issue - both direct human exposure, and degradation of exposed surfaces and equipment.
lived with candles and kerocene lanterns, etc for years and the odd bug will go nuts and spiral in, but not very many
but all in all, there are way less bugs everywhere now
133 comments:
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.
I second this. When my home was infested by flies (I stopped counting at ~1000 over a 3 week period) they would always swarm and hang out by my grow lights (full spectrum LEDs) in my kitchen window. It was a great place for fly traps on the flip side.
It is quite possible that flies prefer one part of the light spectrum more than another part, but to say in the title that they don’t swarm at LEDs is misleading at best.
Might be something to do with PWM.
Also the light bulbs have excellent performance at "catching" bugs because they land on hot stuff and die. I had some GU-12 ceiling halogen lights in my previous apartment and the rims were always covered by bugs that decided to land there and as they were hot from halogens, boom, bug destruction machine
Its possible grow lights emit a bit of uv.
I would even say it’s very likely. Most Blue LEDs emit UV, and a lot of other-coloured LEDs are blue with a phosphor coating
Insects are attracted to low wavelength light, which includes both UV and blue light. Cool color LEDs are usually blue LEDs, and are often used for headlights/etc because they get higher lumen ratings for the power used. Headlights/lightbars are also really bright compared to porch lights.
If you compare an incandescent soft white porch light to a similar brightness soft white led light, you will probably see dramatically more insects at the incandescent bulb. .
From TFA:
> We found that LEDs attracted significantly fewer insects than other light sources, but found no significant difference in attraction between the “cool” and “warm white” LEDs.
All white led is Blue/UV led.
This is actually many many millionth's of some fraction of a percent false! ;)
https://news.ycombinator.com/item?id=50327058
Yep, my Fenix headlamp and flashlights attract flying insects like crazy.
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.
The color configurable bulbs or the high CRI bulbs typically use a 400nm led source and some do use a 380nm but those are much rarer and expensive. Also almost any amount of plastic or glass will significantly absorb that wavelength of UV.
I have a 405nm laser pointer and it makes certain things (any% titanium dioxide) absurdly bright from fluorescence. So you probably aren’t getting UV from those bulbs, but certainly some IR.
You don't need UV to stimulate florescence. 395nm blue light will cause yellow highlighters to light up quite brightly: https://par.nsf.gov/servlets/purl/10326338
UV-A starts from 400nm, so there is no "395nm blue light"
400nm by virtue of aggressive rounding. 395nm is well inside the visible range.
Yeah, we have solar powered LED lights in the walking path where I live and the lights are covered with them. They look nasty.
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
This. It likely depends on the driving technology. Some repell me too :P
Note you can make LEDs dim without PWM via constant current drivers, just less efficient as the duty cycle is 100%, they look much nicer though
PWM drivers should be banned, the quality of lighting is horrendous and it murders LEDs. You have an rms currernt that is in spec but the peak is way too high.
anecdote: I work in a factory, we have thousands of light fixtures. The older constant current LED fixtures have lasted a decade, the new PWM driven lights have had a ~1% failure rate.
How do you know the difference? Constant current is almost certainly a PWM controlled buck/boost regulator. The flicker is attenuated by inductance, more or less depending on the design.
Use a fidget spinner to see the difference. Spin up a 3 lobe fidget spinner and catch the reflection of the LED on it's surface. As the speed changes, a flickering LED will freeze the motion of the spinner. Even more fun with spinners :-).
Yes, adding an inductor will fix the problem, but that costs money. Not enough customers are complaining about the light flicker to justify the higher price.
I guess the distinction is 'filtered' vs 'unfiltered' then. If you look at the lights that fail early using a high framerate camera (1k fps) they flicker between full brightness and fully off. The lights that last longer have some ripple but its 5-10% brightness.
One of my favorite things I read growing up was a passage about what it's like to be a fly watching TV.
In those days TV's were big CRT boxes, illuminated by the electron beam which would race across the screen row by row.
A housefly's "refresh rate" on its eyeballs is much higher than that of a human, so the fly wouldn't see an image as we do, but would presumably find it quite relaxing watching the dot of light slowly move across the screen.
In those days. Oh no! I'm old.
Don't forget about flicker free dimmable LEDs. I install them in my house.
Yeah, while a lot of LED bulbs are bad, some LED bulbs have ever so slightly less flicker than incandescent bulbs.
The streetlights in my neighborhood still have the round photo sensors on top, that have something like a watt of standby current for the sensor itself. I don't think they're trying hard to save powwer.
The ones that have a watt of standby are the really old models (probably not sold for the last 30yrs) where you'd have an LDR controlled relay with no electronics
Anything more modern than that, even if it has a similar case, will use less power
A low-voltage photocell uses like 5mA @ 24VAC these days, it’s nowhere near a watt. You can buy a wireless battery powered photocell or occupancy sensor that will last a decade.
This Acuity occ sensor/photocell combo draws 4mA @ 24VDC: https://pdmassets.azureedge.net/library/SS/documents/specshe...
The article bluntly states: "Moonlight contains ultraviolet (UV) and infrared wavelengths because it is merely reflected sunlight. Insects cue on UV, believing it to be the moon. . . . Incandescent lights transmit UV but LEDs do not. Insects are far less attracted to LED."
However, my mind developed a similar conjecture to your's: what if the common frequencies of PWM occur within a kinetic visual blindspot of insect vision, like human saccades [0] in the novel Blindsight [1], so that insects are not aware of the LED at all?
0. https://www.ncbi.nlm.nih.gov/books/NBK10991/
1. https://www.rifters.com/real/Blindsight.htm#:~:text=%22There...
Are we giving too little credit to the insects?
They've had many generations to evolve alongside all human false light sources. Insect generations are usually pretty short. Perhaps they just find it evolutionary useful to cluster around human sources of light. Presence of human food, liklihood of bumping into other insects of the same species, warmth, etc.
If human sources of light were interfering somehow, they've had hundreds or thousands of generations to breed out that proclivity.
You assume it is possible to breed out without harming other advantageous behaviors which might not be case.
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.
Bugs don’t just materialize out of the ether to swarm lights. Not to feed swallows. They are there and you will encounter them if the density is much more than zero.
There are bugs. You photographed bugs. Maybe more than you would have without lights at all, maybe about the same.
Also better lights don’t necessarily mean perfect lights. We do lots of things to reduce harm. Unfortunately sometimes we do them too much and conserve a significant fraction of the original harm by increasing demand.
>Not to feed swallows.
I often visit a place full of swallows and mosquitoes. The swallows eat mosquitoes, and the mosquitoes eat me. So when I get bit, I joke I'm feeding the birds.
Is that African or European swallows?
The circle of life!
Can we see that? Bet it looks cool.
I was afraid I'd get a "pics or didn't happen" request! Even though that's not that's why you're asking. I don't know that I have the footage any more. I wasn't happy with it, and that was many many moons ago. It's not something I would have spent a lot of effort making copies of.
Could have keyed your external camera flash to a relay driver for the lights. Blinking them on for 1 second every 5 minutes shouldn't get gross moth dust on everything.
Also different insects are blind to various areas of the spectrum LED lights cover. So you just get different creatures showing up.
An incandescent filament bulb will probably give you warmer color in the deeper reds. Too high of a color temperature at night makes things look odd, and you may not immediately notice the HDR capture is skewed.
https://www.amazon.com/dp/B000I17G4O
The neutral "Bright White" Philips A19 Ultra Definition Frosted Dimmable LED Bulbs are about as good as you can get with cheap retail consumer E26 bulbs. Still, the weaker reds may to be an issue depending on what you are capturing, and one may have to drop to a lower color-temperature indoor version like "Soft White". =3
I've experimented with this, but for single images exposing a person at shutter open, and then letting the person leave frame while continuing to expose the sky.
Having a strobe every exposure during a timelapse is annoying though. You'd get run out on a rail at a star party with nonsense like that. Sometimes, it really helps to think about others when doing your own thing and not being an asshat just because you want to do something
Could also try filtered low-pressure sodium lamps, as notch filtering out the light pollution is pretty trivial.
Maybe converting the yellow area of the image into grey scale would give you the highlights, and the color loss could look intentional in moonlight.
There are plenty of intervalometer options around, and even a few Arduino projects for the creative.
Best of luck, =3
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
> Sky is always brighter than the land, moon is not required.
Speaking of things being wrong...how can you come to this conclusion? There are many beaches where turtle hatchlings get confused by all of the lights on land where they crawl away from the ocean instead of towards it. Land is so bright, that the vast majority of humans can no longer see the night sky. So again I ask, how do you come to the conclusion that land is darker than the sky?
I think the missing part is "in the absence of artificial light".
In "the absence of artificial light", please explain how land will be brighter than the sky
It wouldn't, that's his point.
a conclusion can be right even if an argument for it is wrong.
If P then Q, P therefore Q. Q is not the conclusion, it's just the consequent. If P is false, then Q could be true, but claiming Q is true because P is true when P is actually false is a wrong conclusion.
i don't see what point your making.
take something you know to be true. now come up with a stupid, falacious argument for it. now you can see that seeing an argument is bad doesn't mean the conclusion is wrong.
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.
Ever used a blacklight outdoors? They are not bright, but will be covered in bugs.
Don’t those bug collectors (the big white sheets) biologists set up at night usually use UV lights?
And the insect killers in kitchens
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.
I think it’s to do with the LED flicker. You can sometimes see it in your peripheral vision (ie your light/dark receptors) but your RGB cones aren’t as good at spotting it.
Insects eyes are biologically very different.
With LED lighting, if you have lots of spot lights in the ceiling and and open door, you’ll likely find that the light leaving the house is a bath of reflection from different sources inside the house and that likely cancels out the worst of the flicker.
Do they cluster around the bulbs? If not, they might not be attracted to the lights.
Install a single incandescent somewhere and be less mystified by the claim.
They didn't say no bug ever goes to any led light.
But it is what the title on HN says. Is it too much to expect something like "Insects swarm less at LED lights" if that is more truthful?
Probably but is it too much to expect something like reading the article before commenting? We all know that many articles/blog posts titles on the internet are clickbait.
It is not what the title says, either literally, explicitly, or by implication. The title is already exactly fine.
Is it too much to expect super smarty hn developer types to know how to read? Yeah looks like.
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.
I get quite a few insects that fly around a camera, and that is near-ir. So many that a spider finds it worth it's while to build a web in front.
The cozy heat from the IR LED array could be another factor
Can confirm my spiders like cozy heat. I often get them chilling directly above my computer station, legs spread out like a pancake. Presumably there's a warm air current hitting the ceiling. It might also be the light though.
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
There is no such thing as refresh rate for any kind of eye.
There are odd visual illusions though, like humans perceive the Wagon-Wheel Effect even though there's no obvious reason it should happen. This is the effect where the speed of a rotating object varies depending on its sync with a discrete exposure period.
https://en.wikipedia.org/wiki/Wagon-wheel_effect
https://research.tue.nl/en/publications/subjective-strobosco...
You mention it yourself, these illusions only occur with "discrete exposure periods". This is moreso related to video recordings and less about how the eye sees actual physical objects. Such illusions do NOT occur with natural light.
Edit; to be clear there is a version of the wagon wheel effect under natural light, I'm just saying that the main one with discrete exposure periods does not occur irl
> You mention it yourself, these illusions only occur with "discrete exposure periods".
Have a look at https://www.pnas.org/doi/epdf/10.1073/pnas.93.8.3693; my point was that there is documented research that says even with continuous illumination and an (apparently) continuous camera (the brain), this happens:
> The illusion of wheels or other radial patterns rotating back- ward in continuous light, together with the perception of supernumerary spokes, suggests that the human visual system processes sequential episodes of information rather than a continuous temporal flow. In addition to accounting for this remarkable illusion, a strategy of vision that parses the world in this way can explain why movies are so realistic (simply because that is the way we normally see things) and how we detect motion (by comparing the position of the same objects in sequential episodes).
What? Have you never looked at another car's wheel on the highway? Or is that something that only occurs to some people (doubt it).
Eye vibrations can cause the effect to be visible to the naked eye. If even humming can do it, the road vibrations might too.
I'm confused. I thought seeing/measuring lower frequencies due to a low sampling frequency, where the lower perceived frequency is basically the modulus of the real frequency and the sampling rate, is a well-known phenomenon independent of the actual sensor implementation.
I guess it is, but it's unclear why it happens outside of recordings. https://www.livescience.com/32406-what-makes-wheels-appear-t...
I highly recommend the pop science book An Immense World by Ed Yong to disabuse you of this notion. There is a sort of refresh rate (not exactly the same but good metaphor) for everything at every level of living being we study. It gives enough information for you to read the actual studied should you have more questions after reading it.
There is for the visual cortex though.
Try walking outside in a clear night. Look up, notice some stars, or aircraft lights. Now rotate in place, and see how low your vision's FPS is in the dark: the rotation will be visibility jumpy.
An insect, with its much simpler visual processing, and facing a bright light, will likely achieve a much higher FPS, sufficient for the sub-kilohertz flicker to be very visible.
Are you thinking about saccades? I don’t think I’ve ever seen what you’re talking about with non-flickering sources.
For a game i tried to model the behavior of our eyes in the dark and read up on a lot of that stuff. Not once was there a suggestion of jumpy vision. And that is also not my experience. In low light things begin to smudge, lots of ghosting the further in the periphery of your view they move in.
Yeah, i know that's how the physics works, but effectively my computer monitor doesn't flicker for me but a strobe light does. Whatever the proper term for that is what I'm talking aobut
But there is a neurological component in "optical processing" that can be modeled as a discrete rate of update although the underlying physiology is still being investigated.
I can often see the refresh rate of lamps, especially out the corner of my eye.
I'm told insects are more sensitive in that regard, due to having brains with fewer layers.
Nyquist had something to say about that.
It's called the flicker fusion threshold.
They’re missing a lot of variables here.
Never minding IR and UV, not even a visible-light spectrogram of each light source
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.
The study didn't cover high pressure sodium bulbs, the previously popular type in street lamps.
The best light.
The article has an photo of a street full of beautiful golden HPS lamps, and one Guantanamo-grade cold LED.
The outside LED lights on my RV would disagree with this.
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/
They definitely do for my LED desklight.
Wow. I put spotlight on a sheet in the garden to figure out what moths we have. Got nothing, and maybe this is why.
The gold standard for mothing is a mercury vapor bulb. They are pricey and power-hungry, but they'll have your sheet covered in bugs in no time!
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.
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.
There's a Wikipedia entry for that: https://en.wikipedia.org/wiki/Windshield_phenomenon
The answer to that is pesticides. There's still plenty of insects ready to smash into your windshield in many parts of the world.
I wonder what percentage is pesticides vs development? I currently live in an area(US) where a drive to the nearest city of size absolutely coats my car in bugs. US, mostly farmland(soybeans/corn). I wasn't here 30 years ago so can't say there's as many as then, likely not. But if it were only pesticides I'd expect the rural areas to have less bugs than the more developed areas...
As someone who has made many interstate trips through Australia's farmland, I can say that over the decades there's definitely been a drop in windshield splatter. It's unsurprising that pesticide deployed at scale reduces bug populations. Even herbicides which aren't intended as insecticides have limited product advantage to being bug-safe (apart from pollinated crops... and even then). Some aren't even human-safe. An extreme example is paraquat, that while being a herbicide, is irreversibly deadly to humans^ when consumed even in tiny amounts.
^ Obligatory Chubbyemu: https://www.youtube.com/watch?v=0VtUGoGZtI8
I would lean towards the urbanization of the land as well. I rarely get bugs on my car in the city, but as soon as I head out to the country at night my car is covered. I had to stop at a gas station back in May not for gas but just to squeegee the windscreen so I could see again.
Pesticides weren't in use 20-30 years ago? Wouldn't more dangerous pesticides have been in use then, too, compared to now?
They have been used much more massively since the 80s, price decreased significantly.
Yes, and advancements have made them both safer and more effective
wow this would be a neat twist if true - we all defaulted to the negative explanation of having killed them all where a much more positive explanation might be that we're no longer luring them to their deaths at the leading edge of automobiles?
I guess it is most likely some combination of the above, but if there's any evidence it would be a neat reframing
Colorado: "Insect biomass declined by ∼47% and abundance declined by ∼61.5% over the last 35 years." https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2...
Germany: "More than 75 percent decline over 27 years in total flying insect biomass in protected areas" https://journals.plos.org/plosone/article?id=10.1371/journal...
Puerto Rico: "dry weight biomass of arthropods captured in sweep samples had declined 4 to 8 times, and 30 to 60 times in sticky traps." https://www.pnas.org/doi/10.1073/pnas.1722477115
The mass insect-death on windshield issue was as much a daytime issue and nighttime one.
Are you sure about that?
Yes. The daytime crop was always greater than at night
The McFlies don't think very much
My hypothesis is better wind tunnel testing for modern cars so that the bugs go over instead of splatting.
I'd go with fewer people having experience driving not in a city, at least in this forum making the claims as GP
I think they just all collectively got tired of hearing my dad's punny about "it doesn't have the guts to do that again" any time a bug squashed on the windscreen.
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.
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).
It was always a scam because LED bulbs need power supply and that creates heat, switching hundreds of volts ac to low volt dc. They don't last any longer than incandescent in fact they have much shorter lifetimes.
> They don't last any longer than incandescent in fact they have much shorter lifetimes.
The leds do, but the "low-quality" electronic drivers do not and die first. Often well before the advertised lifespan.
They don't last any longer than incandescent in fact they have much shorter lifetimes.
Tell that to my 10 year old Philipps Hue lights. I wonder if there is some other quality at work that would explain the difference...
Average lifetime of my Philips bulbs is ~ 8 months before they develop the 'flicker of death'... at roughly $7/bulb I might as well go back to black market incandescents.
A cheaply made bulb doesn't really support your theory though. Before LEDs, the anti-bug yellow incandescent bulb was available. It puts of a horrendous light and most people didn't like them. It's in the top 3 of lights that I do not like: 1) anything CFL, 2) any cool white (>3600K) light at night, 3) ugly yellow anti-bug light, 4) whatever the ugly greenish light 7-11 uses at some gas stations, 5) 4300K fluoro tubes.
It's in a garden shed, so...
I have noticed that. We have LED porch lights, and never see the usual moths and whatnot.
Without looking at the article, it might be IR related.
Do flames emit UV?
Yes, but how much UV depends on what's burnin / how hot its burning. Otherwise they mostly put out IR.
We use UV/IR combo Flame detectors at work for this purpose.
IIR, hydrogen flames can emit enough of their energy in the UV for that to be a serious issue - both direct human exposure, and degradation of exposed surfaces and equipment.
a little but not much, from my quick look online.
lived with candles and kerocene lanterns, etc for years and the odd bug will go nuts and spiral in, but not very many but all in all, there are way less bugs everywhere now
No but they emit smoke
This is utter nonsense. I live in an RV all summer. Every light is LED, inside and out. They swarm all over the lights.
because they dont emit UV.... a lot of waffle to tell me that
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.
They can. It's either ignorance or malice. It's not economics.
In coastal Florida we require to use turtle-safe light fixtures, mine are 585nm and they didn't attract insects too except potato bugs