Most people think of bees and butterflies when they think of pollinators. However, many plants receive visits from pollinators in the evening and after sunset. Moths, beetles, flies, and even a few bee species remain active in the evening and overnight hours. They help move pollen through gardens and natural areas. Despite their important role, these nocturnal pollinators are often overlooked.
Pollination continues after dark
Many flowers remain open at night and are adapted to nighttime-visiting pollinators. Research is showing that nocturnal pollinators play an important role in pollination networks. While we may not see them at work, these insects help support the reproduction of many flowering plants.
Moths: The pollinators we often overlook
Moths, like the closely related butterflies, are important pollinators. Illinois has approximately 1,700 moth species compared to 150 butterfly species. The often brightly colored, day-flying butterflies catch our attention and are recognized as important pollinators. On the other hand, night-flying moths are often unnoticed because their main activity occurs after dark.
Moths often have a fuzzy appearance because their bodies and wings are covered with scales that help insulate them during cool nighttime temperatures. Some moths hover while feeding and will look for more tube-shaped flowers, while others need a place to land. Clusters of small and large flowers, with a place to land, will be attractive to these moths.
The next time you notice a hummingbird-sized insect hovering around flowers at dusk, take a closer look. It may be a sphinx moth rather than a hummingbird.
Flowers made for nighttime pollinators
Moths are more likely to find flowers with specific characteristics that help them find them in the dark. White or pale colors are more visible in dim moonlit nights. Some flowers release a strong fragrance in the evening, which helps moths find them. While some flowers close at the end of a day, moths are good pollinators of flowers that remain open overnight.
Native Plants for Nocturnal Pollinators
Many Illinois native plants attract nighttime pollinators.
- Missouri Evening Primrose (Oenothera macrocarpa) has large pale-yellow flowers that open in the evening. A plant well adapted to nighttime pollination.
- Foxglove Beardtongue (Penstemon digitalis) has white tubular flowers that are easy for moths to spot in low light.
- Common Boneset (Eupatorium perfoliatum) has clusters of small white flowers that provide a landing pad for nighttime pollinators. The rich nectar resources are a great energy source for night-flying moths.
- Common Mountain Mint (Pycnanthemum virginianum) produces clusters of small white flowers that support a wide variety of pollinators with abundant nectar resources.
- Culver's Root (Veronicastrum virginicum) with its tall white flower spikes made of smaller tubular flowers provides rich nectar resources for many pollinators, including those who are active in low light times of day, like dawn and dusk.
- Obedient Plant (Physostegia virginiana)has pink tubular blooms that attract a variety of pollinators and provide nectar resources into the evening hours.
- Buttonbush (Cephalanthus occidentalis) is a shrub whose fragrant, globe-shaped white flowers attract more than just daytime bees and butterflies. They also provide nectar and pollen for night-flying moths, beetles, and other nocturnal insects. Its dense clusters of tubular blooms and sweet scent make it an important food source for pollinators that remain active after sunset.
Find these and other native pollinator-friendly plants using the Illinois Pollinators Plant Selector at go.illinois.edu/IllinoisPollinators.
Creating an after-dark-garden
You can create a space for nighttime pollinators by using some simple steps.
- Plant light-colored flowers. The light colors make the flowers easier to find in low-light situations.
- Plant in groups. Pollinators can more easily locate food resources when plants are grouped together, thus reducing the energy needed to search for the next nectar source.
- Include fragrant plants. In dim light, the fragrance can be a signal to the pollinator that resources are available.
- Reduce unnecessary outdoor lighting. Bright lights at night can make it harder for pollinators to find floral resources. Light pollution is detrimental to moths and other night-flying insects
- Leave some leaf litter and stems for insect habitat. These insects need a protected place to be during the daytime and throughout the seasons.
- Include host plants for caterpillars. To have adult moths that provide pollination, there must be a place for the caterpillar or larval stage to survive. Host plants provide the food that they need.
These pollinators need our help
Our understanding of the importance of nighttime pollinators is increasing. Research is helping us better understand the importance of nocturnal pollinators and the challenges many of these species face.
- Habitat loss. Without the space and resources, they need in all stages of life, moth and other nighttime pollinator populations decrease.
- Pesticides. Insecticide applications are sometimes delayed to protect daytime pollinators. While this practice can benefit bees and butterflies, it can negatively affect nighttime pollinators.
- Light pollution. Artificial light at night can prevent nighttime pollinators from finding the resources they need.
Most of us never see much of the pollination taking place in our landscapes. While bees and butterflies may get most of the attention, moths and other nocturnal pollinators continue that work throughout the evening and into the night. By including native plants, reducing unnecessary lighting, and providing habitat, gardeners can support pollinators around the clock.
Learn more about Illinois pollinators, explore native plants, and use the Plant Selector tool at go.illinois.edu/IllinoisPollinators.