Learned something new... L.E.D. bulbs do not attract bugs!

[mattl]

Just thought I'd pass this info on if anyone is interested.  I put a clear LED bulb in one of my outdoor fixtures, it's on 24/7 and I noticed that there are no bugs flying around it and no cobwebs.  Doing a little research I found  it's the ultraviolet light that attracts bugs and most, but not all, LED bulbs do not emit Ultraviolet light.

 

I'm planning a summer party next weekend, and I putting up a ceiling fan on my patio and will be putting LED bulbs in.  I've also found that a fan on low speed really helps at keeping bugs away too.

 

[pdub]

Thank You!

This is good info to know. I am tired of the bugs flying over my front door and the spiders they attract. Now I know what I'll be replacing the stanbard bulb with.

 

[kb0nes]

Matt, Out of curiosity what kind of lamp were you using prior to the LED? If we are comparing to an incandescent lamp then something is amiss here.

A white LED is actually an ultraviolet LED that is used to excite a broad spectrum phosphor to attempt to create "white" light. In essence its similar to a florescent lamp although those use UV created by a mercury arc to excite the phosphor. Both LED and florescent lamps leak a fair bit of UV. In comparison an incandescent filament radiates energy when heated, most of which is in the infrared range but some makes it up into the visible spectrum, but very little is ultraviolet. The attached spectral chart shows the comparative UV radiation from both light sources.

So perhaps any difference in bug attractiveness isn't due to ultraviolet light? I'm not questioning your results of less bugs, only questioning the explanation for it. In my case I have an 7w Phillips 1st generation LED (2700K) light in my front door light. When I replaced the CFL, and before that the 40w incandescent, I never noticed any difference in moths etc. that were drawn to the light.

Here is a plausible alternate theory. Many LED lights use a switching power supply that can result in a high frequency (100's of kilohertz) flicker in the light. Most lights filter this pretty well to smooth it but some don't. I wonder if the high frequency flicker could be less attractive to bugs? Can you tell me who your lamp is made by and the wattage/style etc? In case you didn't realize I'm a bit of an LED geek. I have my house almost 100% converted to LED lights now. I seldom go into the Home Depot etc without walking out with a new LED lamp. Tonight it was a 9.5 watt Cree BR30 flood, its lovely and dims perfectly , you can't tell its not a 65 watt incandescent!

 

[arbilab]

Consider that bug zapper lights are ultraviolet. Whilst incandescents are not at all. Yet both copiously attract bugs. If LEDs do not, so much the better.

 

[tolivac]

KBones is correct on the UV emission of common light sources-modern LED lighting equipment does use phosphors excited by UV energy from the LED to produce more useful visible light we see.Older internal phosphor coated mercury lamps did the same thing-and depending on the formula of the phosphors allows the light source to be different colors.Does the UV really attact insects-or is it how things appear to them illuminated by UV lights.Shine a SW UV light on a flower blossum at night nd it looks entirely diffreent than during daytime when bightly lit by the sun-the UV pattern is still there-the insect and some birds still see it-but to us the UV pattern in the flower is washed out by the visible light from the sun.The sun is also a powerful UV light source-early UV expreimenters used it by filtering the sunlight to get UV.Oh yes,CRT's use phosphors to emit light when struck by electrons-same as in plasma TV picture tubes(gas filled)You can shine a UV light source on the screen of a CRT- Color one-and see the color phosphors-this is one way the screens are tested before sealing them into the CRT at the factory.

 

[tolivac]

I have a collection of LED flashlights-next will be the LED bulbs.One flashlight I have can generate 2,200 lumens from a single LED chip.Olight SR 90 series lights.They also make a portable LED light that is almost 6,000 lumens.The 4-7 company makes one that is like 15,000 lumens from several LED chips-but brace yourself-this light cost several grand!But would be fun! a real retina scorcher!

 

[countryford]

We have been slowly replaince the bulbs in the house with LED lights. When we replaced the outside lights, i noticed that the bugs weren't attracted to them. I'm not sure what the reason is, but just like the results.

 

[mattl]

Here is a link to an article explaining the LED/Bug connection.  the gist is if you use the "bluer" 3200k and above bulbs bugs are attracted, is you use the warm white --which I am -- they are not....

http://robled.hubpages.com/hub/Ten-Amazing-Facts-About-LEDLights

 

[kb0nes]

Matt,

Thanks for the link. It appears there is more to insect "attractiveness" to light then simply looking at either end of the spectrum alone. Who knew they were so attuned to light color?

I suppose it makes sense as the old "Bug Light" incandescent bulbs were yellow effectively filtering out much of the cooler bluish light even though a tungsten filament doesn't create a lot of blue light.

I may have to try a test, I have some 2700K and 4000K Philips 800 lumen lamps. Would be easy to run a couple in the backyard and see what we get. I'll post back with a comparison.