There are approximately one hundred thousand aquatic insect species currently known to science and this figure is likely a significant underestimation. The ecology of aquatic insect groups has been studied due to their role as bioindicators of water quality and in the case of Diptera, their role as vectors of disease. Light trapping targets emergent adults, using mercury vapour bulbs or actinic fluorescent tubes, however these light sources are unsuitable for sampling remote regions due to their power requirements, which limit their mobility. Most insects studied have three types of photoreceptors corresponding to UV, blue and green light.
We describe the NightLife: a cheap, robust, portable, LED based light source which targets insect trichromatic vision, is capable of autonomous operation and is powered by a single AA battery. Field trials show that the NightLife is capable of collecting sufficient samples of 12 insect orders, including all aquatic orders commonly collected by traditional light trapping and compares favourably with actinic fluorescent tubes and white LEDs. Future development in LED technology will likely result in LEDs replacing traditional light sources for collecting insects more widely.