Nocturnal Pollinators
Pollination does not stop at sunset with bats, moths, beetles and other insects collecting pollen and nectar at night. These night shift workers are often overlooked, but scientists are beginning to understand the importance of nocturnal pollinators for crops and wild plants. Most plants are still accessible at night and recent research concluded that moths can be more efficient pollinators than day-flying insects such as bees. A three-year study on apple trees at the University of Arkansas Division of Agriculture Experiment Station shows nocturnal pollinators do just as much pollinating as non-native honeybees. Additional research at the University of Sussex concluded that moths can pollinate flowers at a faster rate than day-flying insects. While day-flying insects often have more time available to transfer pollen, moths and other nocturnal pollinators are making important contribution during the shorter hours of darkness.
In recent years many pollinators have experienced large drops in numbers. Threats to nocturnal pollinators include habitat loss, light pollution, and climate change. Learn more about the moths, beetle, and bats providing pollinator services and how the U.S. Fish and Wildlife Service and others are working to support these species.
Moths
In the United States there are roughly 11,000 species of moths. Moths can vary greatly in appearance and size. For example, the white-lined sphinx belongs to a group of moths known as hawk or hummingbird moths, due to their size and resemblance to hummingbirds in flight. With other moth species measuring less than an inch wide with primarily brown or gray coloring to blend in with trees, bushes, and other resting places.
Although some moths never eat as adults, others can be seen feeding on flower nectar or the sugar from tree sap. As moths feed on flower nectar with a coiled tube-like structure called a proboscis, they spread pollen from plant-to-plant aiding pollination as they collect nectar.
In the case of the yucca moth, the insect actively works to pollinate host plants. Without the yucca moth, the yucca plant would lose its only pollinator, and without the plant, the moth would lose its larvae food source for the next generation. These two species are dependent on each other for survival. After a female yucca moth mates, it will visit several yucca flowers collecting pollen. She uses special tentacles around the mouth to carry the pollen to another flower stigma which fertilizes the flower. With the flower fertilizes she then lays her eggs in the flower. The fertilizes flower will produce fruit and seeds that will provide a food source for the moth larva when they hatch.
Beetles: An ancient and important pollinator
Beetles were among the first insects to pollinate flowers, and they remain essential pollinators today. According to the USDA, they are especially important pollinators for ancient plants such as magnolias and spicebush. Fossil records show that beetles were abundant during the Mesozoic period (about 200 million years before present) and continue to be important visitors for woody angiosperm (flowering plants that bear fruits or flowers) species today.
Often admired for their bioluminescence, fireflies are important beetle pollinators found throughout the Eastern US. These beneficial insects are welcomed by gardeners as they feed on pest species and provide pollinator services as they feed on pollen and nectar.
Flower-visiting and fruit bats
Worldwide over 500 plant species rely on bats to pollinate their flowers, including species of mango, banana, guava, and agave. There are over 45 species of bat found in the US including US territories and commonwealths with the majority feeding primarily on insects. The common feeding features of pollinating bats are elongated snouts and tongues, combined with smaller and fewer teeth. This aids in the rapid collection of nectar. Some species rely on echolocation to find flowers and others like the fruit bat use their large eyes and sense of smell to find food. Pollinating bats can be found in the US including species in the Southwest and in the Pacific Island. These pollinating species include the lesser long-nosed bat, Mexican long-tongued bat, and the Mexican long-nosed bat.
The Mexican long-nosed bat, is a migratory species that mostly occurs in Mexico, but there are two main roosts in the U.S. The species mates in Mexico and then the females migrate northward, chasing agave as it blooms further and further north. Once they get up to Texas and New Mexico, they'll locate a roost, give birth and ween their young, and when they’re old enough, they all fly back south.
How you can help nocturnal pollinators
Dim the lights at night
Light pollution is a specific threat to nocturnal pollinators as they have evolved to fly at dusk and nighttime. Pollinators like moths, search for flowers beneath moonlight using low-light vision, and are often attracted to white or pale flowers that reflect moonlight and can be spotted from a distance. Light pollution can attract moths and other nocturnal pollinators drawing them away from plants and causing them to abandon feeding or mating. This can have serious impacts on the pollination process. You can help nighttime pollinators by making small adjustments to your lighting at night at your home or your property. Using black out curtains to keep the light inside your house, dimming your outdoor lights, avoiding bright light and using motion detectors are a few of the ways you can help pollinators focus on their job.
Create pollinator habitat - nectar, host plants and leaves
Like butterflies, bees, and other daytime insect pollinators, nocturnal pollinator habitat protection is key to their survival. For pollinating insects to reach adulthood, the life stage when they provide pollinator services, they have to survive as eggs and larva. The vast majority of butterflies and moths overwinter as an egg, caterpillar, cocoon, or as adults.
Leaf litter is vital for over winter habitat and protection from predators. Often these fallen leaves become the first food for caterpillars when they emerge from eggs. In the case of the luna moth, larval cocoons are disguised as dried leaves to blend in with the environment and avoid predation.
Habitat for these important pollinators also include host plants for moths, beetles, and other insect pollinators to lay their eggs on, and they then provide food for the larval life stage. Host plants are essential with some pollinators depend on only one or two species of host plant for larval and species survival.
You can help by planting native pollinator gardens and including host plants where appropriate. When purchasing plants for your garden, look for native plants if possible, or for plants that are “pollinator safe” and not sprayed with pesticides and neonicotinoids.
