Early “purple” LEDs were often marketed as blacklights or ultraviolet sources despite not emitting within the ultraviolet spectrum. As a result, these lights performed poorly for insect attraction and developed a poor reputation among entomology enthusiasts.
Advances in LED technology have since made true UV LEDs available. Within the ultraviolet A (UV-A) spectrum, the available wavelengths are 365 nm and 395 nm. Entoquip lights incorporate both wavelengths to cover as much of the UV-A spectrum as possible.
While 365 nm LEDs may appear dimmer to the human eye, this is because a greater proportion of their output lies outside the visible spectrum.
A common misconception is that LEDs do not attract insects. This belief arose because most standard LED colors emit narrow bands of visible light and do not extend into the ultraviolet range.
When LEDs emit true UV wavelengths, they are highly effective at attracting nocturnal insects. Modern UV LEDs produce narrow, well-defined UV bands that overlap the spectral sensitivity of many night-flying insects.
In our own field tests using the Entoquip light, performance was comparable to traditional fluorescent UV tube lights (e.g. BioQuip) in both species diversity and specimen abundance.
We did not observe a significant difference in attraction between 365 nm and 395 nm LEDs under typical field conditions.
Multiple peer-reviewed studies have evaluated the performance of UV LED light sources relative to fluorescent UV lamps.
Zemel & Houghton (2017) compared a portable LED light containing nine LEDs to a standard 15-watt fluorescent UV tube. Across multiple wavelengths — including those used in Entoquip lights — they found no significant difference in mean specimen abundance or ordinal diversity.
Similarly, Green et al. (2012) found no significant difference between an 18-LED 395 nm UV light and an 8-watt fluorescent UV bulb in sampling emerging aquatic macroinvertebrates.
When emitting true UV-A wavelengths, UV LED lights are highly effective at attracting night-flying insects. Field results and published studies consistently show performance comparable to traditional fluorescent UV sources.
Combined with their durability, energy efficiency, and portability, UV LED systems represent a practical and effective alternative for nocturnal insect sampling.
Zemel, R. S. and D. Houghton. 2017. The ability of specific-wavelength LED lights to attract night-flying insects. The Great Lakes Entomologist, 50(3-4): 79–85
Green, D., D. Mackay and M. Whalen. 2012. Next generation insect light traps: the use of LED light technology in sampling emerging aquatic macroinvertebrates. The Australian Entomologist, 39: 189–194.
