Fluorescent ligthing. Do they attract more bugs than incandescent?

[AC/DCdude17]

It appears there are more bugs around my fluorescent lights
than incandescent lights. Is it just a coincidence or does the spectrum
of fluorescent attracts insects more than a simple 2800K black body
radiator?

 

[John D. Bullough, Gurley Building]

It appears there are more bugs around my fluorescent lights

than incandescent lights. Is it just a coincidence or does the spectrum
of fluorescent attracts insects more than a simple 2800K black body
radiator?

Depends on the fluorescent spectrum you have.

The Illuminating Engineering Society of North America Lighting
Handbook doesn't give very specific numbers but says many types
of insects are attracted by near UV and short-wavelength ("blue")
visible light more than long visible wavelengths ("yellow" and
"red"). Apprarently some types of insects are attracted to IR
too, so incandescent might actually attract different types of bugs.
But there does seem to be something behind the yellow "bug" lamps
that many ice-cream stands have in the summertime.

 

[Clive Mitchell]

Flicker rate seems significant to me. I have homebrewed experimental
bugzappers, including varieties with different color-type fluorescent
lamps and different power supplies for said lamps. It seems to me that
120 Hz flicker is visible to most flying insects. I have achieved a
large improvement in kill rate by operating the attractant blue or UV
fluorescent lamp from filtered DC (easiest with extra resistance losses)
than from AC.
My scheme: Rectify and filter 120V AC. Filter capacitor is in the
100's of uF. Please have a 1/2 amp or so fuse in one of the AC leads
in case something goes wrong.

Remember that running the tubes on DC tends to cause mercury
polarisation quite quickly and also tends to be a bit rough on the
cathode end of the tube. Are you saying that the 100/120Hz flicker
makes the lights less attractive to insects?

Has anyone tried clusters of LEDs for insect attraction? I'm sure I saw
an advert for a product that used a green LED as the attracting source.

 

[Clive Mitchell]

Has anyone tried clusters of LEDs for insect attraction? I'm sure I saw
an advert for a product that used a green LED as the attracting source.

After a quick search of the 'net I can answer my own question to some
degree....

The link below shows an interesting experimental whitefly trap that uses
a "lime green" (530nm) LED to attract the insects. This also tallies
with Sams laser faq mentioning the effect of a high power 532nm laser
being shot into the air and the resultant rainfall of toasted insects.

http://www.ars.usda.gov/is/pr/2002/020530.htm

Another reference to this device is as follows:-

"Technical Abstract: Modifications of CC whitefly traps are in progress
to improve their potential for adult whitefly control in greenhouses.
Adult catches in the modified CC traps have been increased by 50% by
coating trap tops with Tanglefoot and removing the deflector plates. In
laboratory studies, installation of a lime green LED light in the trap
top resulted in catches of 281 adults/trap/24-h compared with catches of
18 and 12 adults/trap/24-h for traps with white LED light and no light,
respectively. Studies are in progress to test the effects of the
modified CC traps on catches of whitefly parasitic wasps. "

That's an increase of 2300% in the traps that had a green LED added. I
bet the researchers had that WAAAAHEY! feeling when they found the
filled traps the next day. The lower count in the White LED traps
suggests that either the other wavelengths are deterring the insects, or
the white LEDs didn't have a dominant peak in the required wavelength.

Since the inverted cup style traps are used out in fields to try to draw
insects away from the crops, I guess that a really neat idea would be to
couple the natural sunshine with the LED technology by making a trap
that worked like a solar powered garden marker. This would charge
during the day and light the LED at night when the trap is most
effective. (And if that's not patented yet, then you can't now, 'cos
I've just disclosed it publicly.)

A search for other forms of fly traps found various versions of a home
made glue board, which were basically bits of yellow plastic covered
with a thin film of Vaseline, or alternatively a mix of Vaseline and
detergent (Do they mix?).

It follows that if anyone wants to experiment with LED based fly
catching effectiveness, then all that is required is a bit of card or
plastic smeared with Vaseline, an LED, resistor and battery pack.

Since it appears that some insects are quite colour selective, it would
probably be a good idea not to put more than one colour of LED on the
card at a time. (But don't let me stop anyone experimenting?)

I wonder what my chances are with catching bugs on the windowsill of a
top floor tenement flat.

 

[Don Klipstein]

Do I understand you correctly? You are operating these fluorescent
lamps directly from DC power (with a resistive ballast). Is that
correct? Don't you have problems with cataphoresis, in which the
mercury gets pumped toward the cathode (negative) end of the lamp,
leaving the anode end of the lamp deficient in mercury? Perhaps your
bugs like the Argon spectrum that is generated in the absence of
mercury at the anode end of the lamp

I have seen this phenomenon at other times, but I seem to have gotten
away with running F15T8 and F20T12 lamps with steady DC without one end of
the lamp going dim.
The lamp was vertical. I do not remember which end I had up. Now that
think about it, if I keep the negative end up there may be an adequate
amount of mercury vapor throughout the lamp.

- Don Klipstein ([email protected])

 

[AC/DCdude17]

X-No-Archive: Yes

My lamps are 5,000K tri-phosphor on electronic ballast.

 

[Victor Roberts]

I have seen this phenomenon at other times, but I seem to have gotten
away with running F15T8 and F20T12 lamps with steady DC without one end of
the lamp going dim.
The lamp was vertical. I do not remember which end I had up. Now that
think about it, if I keep the negative end up there may be an adequate
amount of mercury vapor throughout the lamp.

How long have you run these lamps on DC? If the lamp has a lot of
mercury and has operated for a fair amount of time, it may take days
to move enough mercury to see mercury depletion at the anode end.

 

[Don Klipstein]

How long have you run these lamps on DC? If the lamp has a lot of
mercury and has operated for a fair amount of time, it may take days
to move enough mercury to see mercury depletion at the anode end.

It was a few hours an evening for a couple weeks.

If I had the anode end down, possibly gravity may have maintained the
mercury supply there. This was late in the 1970's when fluorescent lamps
often had enough mercury to form a noticeably visible drop that can roll
around.

- Don Klipstein ([email protected])

 

[Janne Sinkkonen]

It appears there are more bugs around my fluorescent lights
than incandescent lights. Is it just a coincidence or does the spectrum
of fluorescent attracts insects more than a simple 2800K black body
radiator?

In general insects favor near-wavelength ultraviolet light. Mercury
vapour lamps (peaking below ~ 380nm) without fluorescent material in
the bulb are often used by professional and amateur entomologists to
attract moths and other insects, and they work much better than
incadescents.

Special-purpose fluorescents radiating around 352-358nm are used in
commercial insect traps (that kill with high voltage), and the results
are even better if green wavelengths are added - this kind of
fluorescents are sold under the brain Insect-o-cutor and soon
(already?) also by Sylvania. 406-410nm is said to be not that good at
attracting moths.

Exceptions to these general rules are probably numerous, including
some geometrid moths that favor yellow light.

Generally, insects are attracted by light either because they try to
get to open places, or because they use the light for orienteering and
are fooled by light being near them - keeping the flying angle
constant to the light source with the intention of flying at a
constant direction fails for near-by lights and often causes a spiral
towards the light source.

I do not know the ecological reason for attractiveness of UV, but
probably it has something to do with 1) night-time light available, and
2) reliability of the UV light as an orienteering aid.

 

[Janne Sinkkonen]

Oh well, I should really proof-read my posts before sending...

In general insects favor near-wavelength ultraviolet light. Mercury ^^^^^^^^^^^^^^^
near-visible

fluorescents are sold under the brain Insect-o-cutor and soon

^^^^^
yes, brand