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points by tw04 3 days ago | 0 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.

[–] Izmaki 3 days ago

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.

[–] InsidiousWombat 3 days ago

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

[–] Freestyler_3 3 days ago

Its possible grow lights emit a bit of uv.

[–] joshspankit 3 days ago

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

[–] _heimdall 3 days ago

Aren't full spectrum grow lights intended to emit UV?

[–] Izmaki 2 days ago

Oh yes, 100%. It's full-spectrum, so there's absolutely UV light. :D My basil and avocado plan love it.

[–] almog 3 days ago

Same. I use my headlamp red beam when they start to swarm, they immediately fly somewhere else. If I camp somewhere with high bug pressure to the point that they try follow me into my tent, I'd actually use the white light to lure them away by attaching it to the apex of my tent while I settle inside before grabbing it quickly.

[–] mitkebes 3 days ago

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. .

[–] motionlessveloc 3 days ago

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.

[–] IAmBroom 2 days ago

Your phrase "low wavelength light" is odd... I figured out you meant "short wavelength light", which is high energy/frequency, on the blue to UV end.

[–] mrheosuper 3 days ago

All white led is Blue/UV led.

[–] nomel 3 days ago

This is actually many many millionth's of some fraction of a percent false! ;)

https://news.ycombinator.com/item?id=50327058

[–] raxxorraxor 3 days ago

I have a pure LED desktop lamp and can also say that insects swarm to them as well as my monitors.

There probably are insects that don't perceive the "thinner" spectrum, but generally it (sadly) isn't true.

[–] wopwops 3 days ago

Yep, my Fenix headlamp and flashlights attract flying insects like crazy.

[–] eth0up 3 days ago

My nichia based Acebeam, Fenix and Zebra as well. Florida is a good place to test this.