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Monochromatic Light As a Species-selective Insecticide
An anonymous reader writes: The harmful effects of ultraviolet light have been long known. But now researchers at Tohoku University in Japan claim that visible blue light is also lethal to many insects, possibly even more so than UV, even at reasonable daylight intensities. Moreover, they report that certain species are more sensitive to specific wavelengths: Given the same intensity (3x10^18 photons/sec/m^2), light in the 440-467nm range was far more lethal to fruit flies than light of longer or shorter wavelengths. The wavelength 417nm was three times as effective at killing mosquito larvae than the shorter 404nm light, contradicting the notion that higher-energy photons always cause more damage. The research has wide implications for modeling the effect of natural and manmade environmental changes on insect populations and for selectively controlling populations of certain species.
This sounds like something that evolution would beat-out in two years flat. Visible light harming members of a population differently. . . how many generations do you think it would take?
"If you wanted to generate that much via a LED bulb with an external quantum efficiency of 20% then it'd take only 6,5 watts."
At what distance from the plants?
"Is it really possible that a little 6,5W blue LED bulb could kill all the fruit flies in a square meter box - are insects really that sensitive to light?"
Yes, they are, which is why I'm selling a combo UVB-420nm broad-spectrum light to greenhouses for pest control and also additional plant lighting. I learned about the effects of blue light long ago when I decided that then-current leds using a shit 8:1 red:blue ratio were not providing enough in the blue range, and pumped to 4:6.
Spidermite problem, GONE. One of the WORST infestations to battle, wiped the fuck out, nuked from orbit.
Still waiting on Serviscope_minor to wake up to fucking reality and realize that Jessica Price isn't going to fuck him.
It would appear that this is about the same wavelength that many plants want. As such, by sweeping over plants with high levels of it for short periods, it might help the plants while at the same time, killing pests.
Way cool.
I prefer the "u" in honour as it seems to be missing these days.