Moths
Moths quietly pollinate plants while we sleep. They play a critical and often overlooked role in moving pollen, setting fruit, and supporting healthy ecosystems. While moth populations have been declining for decades due to habitat loss and climate change, a less visible but increasingly important threat is artificial light at night. Outdoor lights disrupt feeding, navigation, and reproduction for nocturnal insects.
How Moths Pollinate
Like butterflies, moths do not intentionally collect pollen. Instead, pollen grains cling to their bodies and their long, straw-like tongues (called a proboscis) as they drink nectar. That pollen is then carried from flower to flower. Because different species fly at different hours of the night, a single garden may host a rotating cast of moth pollinators from dusk through dawn.
Note: Moths do not have jaws so they do not actively eat pollen. But, small amounts of pollen may be ingested with the nectar, enabling limited absorption of proteins and other nutrients.
Flowers Made For The Night
Moth-pollinated flowers tend to be white, pale yellow or pale pink. The flowers are typically in clusters, open late afternoon or night, and are ample nectar producers. They usually have a strong, sweet fragrance as night-flying moths depend heavily on a developed sense of smell for feeding and reproduction. Hawkmoths can detect the scent of a flower over a mile and a half away! With days of working long hours and some with equally long commutes, gardeners are increasingly enjoying night-blooming flowers by planting aptly-named "moon gardens".
Moths and Food Crops
Moths are just starting to get the credit they deserve for pollinating food crops (yucca, tobacco, lowbush blueberry, cranberry). In lowbush blueberry, berries produced solely through nighttime pollination were equal in weight to those pollinated during the day, showing that moths are highly efficient pollen movers (though lower fruit set was observed overall).
Not all moths are beneficial in an agricultural setting. For example, cutworm moth larvae occasionally damage our red raspberry canes but outbreaks are kept in check by growing a diversity of berries on our farm (i.e., increasing habitat complexity).
Light Pollution: A Hidden Threat
Night-flying moths use the moon to navigate. Because the moon is so far away, the moth perceives that the light rays are coming from the same general direction. The moth is able to fly in a straight line by keeping these rays at a constant angle to its body.
Artificial lights change everything. Streetlights and porch lights radiate light in all directions. The moth desperately tries to keep these rays to one side of its body, changing flight direction in all topsy-turvy ways to compensate. The artificial light confuses the moths and distracts them from visiting fields, gardens, and flowers. Studies have shown:
- Fewer moths at ground level in lit areas
- Fewer moths carrying pollen in lit areas
- Reduced pollination, fruit set, and seed production
- Losses not compensated for by daytime pollinators
White and blue-rich lights are especially disruptive. Warmer, amber-toned lighting (2200 Kelvin) is far less attractive to moths and other nocturnal insects.
👉 Want to make a difference? Switch to amber outdoor lighting
Why Moths Matter Beyond Pollination
Moths are key food sources for owls, bats, frogs, and birds (eating caterpillars and catching moths at dusk and early night). When moth populations decline, the effects ripple throughout the food web. Darkness is not an absence. It is a habitat.
References
Cutler GC, Reeh KW, Sproule JM, Ramanaidu K. 2012. Berry unexpected: Nocturnal pollination of lowbush blueberry. Canadian Journal of Plant Science 92(4): 707–711.
Eva Knop, Leana Zoller, Remo Ryser, Christopher Gerpe, Maurin Horler, Colin Fontaine. 2017. Artificial light at night as a new threat to pollination. Nature.
Macgregor et al. 2016. The dark side of street lighting: impacts on moths and evidence for the disruption of nocturnal pollen transport. Global Change Biology.