USC professor develops innovative indoor lighting
USC professor Travis Longcore’s has developed indoor lighting that attracts fewer insects.
This development alters the currently popular LED and fluorescent lights, which use all wavelengths of the color spectrum evenly.
Consumer electronics company Philips Research asked Longcore to work with them to test indoor lighting options that would minimize insect attraction. At the time, Longcore was an adjunct professor at both UCLA and USC, and he brought Philips Institute’s research quandary to the senior research practicum he led during the winter and spring quarters for UCLA’s environmental science major.
“[The UCLA students] had developed some technology for being able to take custom [LED] bulbs and create a similar color of light in many different ways,” Longcore said. “Even though we may look at a light and say ‘it’s all white,’ you can create that color by mixing different wavelengths in certain ways.”
On the light spectrum, wavelengths smaller than 500 nanometers, which produce blue, violet and UV, generally attract arthropods. Lighting with reduced ecological impacts is already used outdoors — on street lamps for example — so insects are less attracted to these than to a light that emits blue wavelengths. However, these outdoor lights are far too yellow for indoor use; humans prefer white lights, which generally emit the full color spectrum.
Longcore and his seven-student team work builds upon this intersection between human use and insect behavior, establishing that LED lights can be manipulated to omit blue lights, reducing insect attraction, but still appear the same as full-spectrum LED lighting to the human eye.
During the spring quarter, the students implemented their research design and placed various kinds of lights over pan traps in urban and rural environments in Los Angeles.
Over 32 separate nights, students caught insects under compact fluorescent, commercial LED and customized LED lights. Traps under the lights customized for decreased attractiveness caught significantly less arthropods than the fluorescent and commercial LED lights, which are similar in color spectrum.
The implications of developing this sort of light include not only reducing general discomfort from the presence of insects indoors at night, but they are also a first step in bringing efficient lighting that could reduce exposure to insect-borne diseases such as malaria.
Malaria infections are common enough in equatorial countries that global health studies senior Evan Pye, who has lead two Alternative Summer Break projects in Uganda affirms that “nearly everyone in Uganda has caught malaria.”
Pye explained the common malaria prevention method is to install bednets, sometimes sprayed with anti-mosquito solution. According to Pye’s notes while studying the health and income of a sampling of rural Ugandan village members, bednets are effective at preventing malaria as long as there are no holes in them; they deteriorate quickly and last about a year.
Pye also explained that underdeveloped infrastructure poses distribution problems even if additional nets are available.
Nearly 68percent of the arthropods the Longcore’s research team caught belonged to the order Diptera — which includes flies and mosquitoes. Lepidoptera —- moths and butterflies — composed 12 percent of caught insects.
Researchers sorted insects caught according to orders rather than family or species, and knowing which order won’t be attracted to a certain light is relevant when predicting which insects will carry disease.
“Orders can still tell us whether or not [insects] be disease-carriers in the tropics,” Laina Petrinec, one of the study co-authors said. “Diptera and Hemiptera carry most of the diseases, while Lepidoptera does not pose a danger.”
Petrinec says the light study points researchers in a direction to further analyze reducing insect-borne disease prevalence in moist tropical regions without compromising the ability to use electric light for indoor night use.