Diurnal, or daylight pollinators such as bees and butterflies, have long been considered the champion workhorses in their field; however, a paradigm shift is slowly occurring that brings to the forefront the overwhelming contributions of nocturnal Lepidoptera pollinators: the moths.

Unlike bees, many moths have an obviously fuzzy body. This fuzzy underbelly ingeniously collects pollen from the plant providing the moth with nectar and, as it flies onward, the pollen is then deposited upon the next plant, and so on. While bees tend to forage closer to their nesting location, moths will often travel significant distances navigating by moonlight at a greater height searching for delicately pale leaves and aromatically scented blooms below from which to obtain nectar and indirectly pollinate. This characteristic likely plays a larger role in promoting genetic diversity across plant communities outside the range of diurnal pollinator landscapes. Furthermore, since moths visit such a diverse variety of plant species for nectar, pollination efforts for those plant species also visited by diurnal pollinators see a dramatic increase in overall pollination due to the overlap in the pollinator subgroup efforts. Although the order Lepidoptera encompasses both butterflies and moths, the diversity in the moth world is incredible. Consider the sheer numbers for a moment: there are about 140,000 species of moths versus about 20,000 species of butterflies. Meanwhile, bee species in the United States number a mere 4,000 of the 20,000 species known worldwide.

Concurrent with the rising tide of acceptance and study involving the moth as a premier, albeit nocturnal, pollinator for native plants, scientists across multiple disciplines agree that light pollution is easily as significant a threat to these nocturnal pollinators as are loss of habitat, climate change, pesticide exposure, invasive species, and disease. Indeed, various studies spanning the past six years from various parts of the globe have established that light pollution not only adversely affects nocturnal pollinators, but also negatively impacts diurnal pollinator-plant interactions. It should come as no surprise that this adverse condition created and advanced in the last century affects not only the industrialized countries but is quickly spreading across developing nations as well with the impetus being the scientifically unfounded notion that continuously lit environments will provide a greater degree of both roadway and personal safety.

The most recent “world atlas of artificial sky luminance” (published in 2016) found that Singapore was suffering 100% light pollution to the extent that the populace was no longer able to achieve full night vision. The intensity of light pollution at this level has been found to alter circadian rhythms, depress melatonin levels, and increase cortisol levels all of which have profound impacts upon both physical and mental health. The United States contains multiple massive metropolitan areas suffering the same fate and, for more than a decade, it has been demonstrated that 80% of North American citizenry are unable to see the Milky Way. An unintentional consequence of continuous commercial and residential light is the creation of skyglow/light domes which are visible for hundreds of miles. This disruption of darkness necessary for nocturnal animals is not only adversely affecting those heavily populated centers but is resulting in cascading disruption and harm to natural landscapes, agricultural lands and animal life for hundreds of miles. Consider that the light pollution over the Los Angeles basin is visible over 250 miles away in the Mojave Desert. If we use a recent study targeting pollination levels and fruit set alone when light pollution on the blue spectrum is present, we could assume 60% fewer plants being successfully pollinated and 13% lower fruit set for the multitude of Central Valley agricultural fields within 300 miles of Los Angeles or Las Vegas.

Moths require moonlight to navigate and orient themselves during flight high above the landscape; both listening for predators (bats) as well as searching for the floral aroma of plants providing nectar. The entire lifecycle for moths, whether they are successfully pollinating all night long or providing bats and other nocturnal species with food depends upon their survival. Studies have verified that roadway and neighborhood light poles casting light downward and/or outward disorients moth distracting them from their foraging, exhausting them to death by circling the light endlessly and often making them easy prey to nocturnal predators in number far in excess of the norm. The lights bulbs themselves are as much the problem as is their continuous use and ill-conceived illumination trajectory. Scientists agree that the extensive replacement of incandescent bulbs with broad spectrum white light LED bulbs across all sectors of any city presents a viable threat given that most moths are irresistibly drawn to these “blue light” pools. We have all witnessed moths flying into the screens of our devises, into overhead floodlights, into streetlights and into headlights to name a few. The light spectrum of both devices and LEDS bulbs, considered as a cost saving device for individuals, companies and municipalities alike, represent an ecological threat to our nocturnal pollinator populations, as well as the other forms of animal life that depend on the availability of these insects for their own lifecycles.
Consider entomologist Akito Kawahara's simple message about these essential animals, “We can't live without insects. They are in trouble. ....”. He deftly points to the $70 BILLION estimated U.S. economic contribution these animals make through waste disposal and pollination as a method of demonstrating their vital importance to the world at large. If, indeed, we accept the premise that at least 40% of insect populations are in decline for reasons brought about by human activities, then Kawahara proposes “...people can also be part of the solution” by adopting simple changes with both immediate and long term benefits: -Dim or turn off your lights at night; -Install motion sensors for any essential exterior light sources and save on utility bills; -Use red or amber bulbs which are less attractive to insects; -Mow less and encourage natural habitat and food reservoirs for beneficial insects; -Dedicate 10% yard space to native landscapes to both attract and feed pollinators; -Use insect-friendly soaps and sealants-broad spectrum insecticide kills everything; -Ditch the bug-zappers - science has proven they do not kill predators; and -Become an insect ambassador by learning about all insects in your yard. Dr. Gretchen LeBuhn, an ecologist studying the effects of human induced landscape change on pollinators also suggests getting involved locally. Her “Great Sunflower Project” saw over 60% of participating individuals who found themselves unable to contribute actual data for her research because no insects were available to be counted in their metropolitan area, effecting at least one change to their immediate landscape in an effort to attract both diurnal and nocturnal pollinators back to their communities.
Although light pollution has not found its way into mainstream focus by governing bodies worldwide, scientific inquiry and investigative focus have shifted strongly in the past decade to spotlight it as a threat that could be substantially reversed if given the proper attention. Many scientists across multiple disciplines are turning to public involvement in hopes of turning the tide back in favor of co-existence with the animals necessary to human existence.