UV Lights

[Leptraps at aol.com]

Rich / Ian:

I also design and build free standing rigs (setups) for collecting nocturnal 
insects. As a result, I have experimented with virtually every size and watt 
MV bulb and UV straight tube. I have never heard of a parabolic sheet. If you 
have the article/thesis available, I would very much like to read it.

I have never found self ballasting bulbs very effective when used alone. Add 
some UV tubes, and they work well together. I have been told that the current 
process for manufacturing self ballasting bulbs actually over powers the blue 
with white in the light spectrum. Increasing the blue with UV corrects the 
white. I have no documentation to prove these statements. However, place your 
160 watt MV above your 15 watt UV tube on a wall and I think you will see a 
tremendous difference. And the cats won't come near the 160 watt bulb. It 
"hurts" their eyes.

The inside of some MV bulbs are coated with a UV blocking material. There is 
a number on the bulb. The only letters should be "MV." If the "MV" is 
followed with a "C" of "P," the UV light is being altered. Also, the purity 
of the mercury material in the bulbs arc chamber will effect the performance 
of the bulb. If you want some truly boring technical reading, get a copy of 
any book that deals with the technical design of light bulbs. Gray and 
Collins 1966 book "Advances in Light Technology" explains how bulbs "work." 
Krakowski 1949 work entitled. "Let there be Light" explains the light 
spectrum in great detail. If you like some great boring reading, enjoy!

The rig that I built for my own use is 96 height by 88 wide. I use a double 
mount (One for each side of the sheet) of 175 Watt MV.  Two double mounts of 
40 Watt BL UV and BLB UV tubes. At both upper vertical top joints I mount 
either a double or single mount 250 Watt sun lamps. I can turn off any part 
of the lights during operation. A partial picture of one off my sheet setup 
appears in the News of the Lep. Soc. 1999 Vol. 41, No 4. Another partial 
photograph appears in the Arizona Lep. website.

During the 1999 Lep. Soc. meeting in Arizona, moths literally covered both 
sides of the sheet every night we used it. We depart for Arizona in several 
weeks for a collecting trip and two of these free standing rigs will be with 
us. I intend to light up Arizona!

The effectiveness of your UV/MV lights in your area will be determined by the 
brightness of urban light reflection, the moon and the moth population.  I 
have learned that weather, urban reflection, the moon and adult moth 
populations will determine the results. In the Florida Keys, the mosquito 
control spraying that was done for years severely effected insect 
populations. Once it was stopped, the moth population had a recovery. 
However, some species were never seen again.

I have seen 1000 watt MV bulbs draw in thousands of moths. I have also seen 
them draw in virtually nothing as well, while a 15 watt light trap several 
hundred feet away is full. 

I cannot explain why these things happen. I do however, know what works for 
me. I also know what works for me may not work for you. As I said above, I 
think I know why. I just have no real proof.  

Have you taken many butterflies at your lights? Since I began to keep a 
record, I have recorded 64 species of butterflies drawn to UV or MV light. I 
have taken more butterflies at UV than MV. While lighting up Black Mountain 
last weekend with my rig and 15 watt light traps, I took a Speyeria cybele in 
a light trap.

Cheers,

Leroy C. Koehn
202 Redding Road
Georgetown, Kentucky
USA          40324-2622
Tele.: 502-570-9123
Cell: 502-803-5422
E-mail: Leptraps at aol.com

"Let's get among them"
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