Moths are the unsung heroes of pollination

May 13, 2020, 3:54 p.m.
An hummingbird hawk-moth feeding nectar from woolly thistle flower.
Photo: Vlasto Opatovsky/Shutterstock

Meet the pollinator that does its best work at night. That's right. The modest moth. You may have been expecting something a little flashier. A firefly, perhaps.

But, as Travis Longcore, a scientist at the Urban Wildlands Group, told Tom Oder for an earlier story, "Often in nature it's the things we don't notice that are doing a lot of the work."

And this little ball of winged fuzziness turns out to be a pollinating dynamo. In fact, according to a new study from the University of London College, moths — most often seen malingering under street lamps and porch lights — may be more effective at spreading pollen than their daytime counterparts, bees and butterflies.

The research, published this week in Biology Letters, suggests moths maintain a pollen transportation network across the English countryside that may be crucial to crop yields. That may be because while moths visit many of the same plants as bees, they also attend plants that their buzzing brethren pass over. As a result, their work complements that of bees, filling in ecological gaps and ensuring pollen from a diversity of plants is carried far and wide.

"Nocturnal moths have an important but overlooked ecological role," notes study lead author Richard Walton in a press release. "They complement the work of daytime pollinators, helping to keep plant populations diverse and abundant. They also provide natural biodiversity back-up, and without them many more plant species and animals, such as birds and bats that rely on them for food, would be at risk."

It's easy to overlook the pollinating prowess of moths — especially since they lack the clearly defined proboscis that bees use to hoover nectar from flowers. They somehow come off as shaggier, even more bumbling versions of bumblebees. But it's their very shagginess that helps them gather the goods.

"Settling moths sit on the flower while feeding, with their often distinctly hairy bodies touching the flower's reproductive organs," Walton explains. "This happy accident helps pollen to be easily transported during subsequent flower visits."

While scientists are just beginning to track the extent of their influence, moths' nighttime labors aren't exactly a secret. In a previous study, researchers from University of London College found moths spread pollen across much greater distances than more localized bees.

"While bees are excellent pollinators, they will only travel within the local environment of the nest," that study’s lead author Callum Macgregor explained in a 2018 press release. "Moths appear to complement the work of bees and can carry pollen over greater distances as they don't have the same ties to a particular part of the landscape. Potentially, this might help to prevent inbreeding among plants."

Indeed, the more we learn about the secret life of moths, the more we may come to appreciate the labor they perform on the night shift — working at least as hard as bees to bring our daytime world to life.

"In recent decades, there has been a lot of science focus on solitary and social bees driven by concerns about their dramatic decline and the strong negative effect this has had on insect-pollinated crop yields," study co-author Jan Axmacher explains in the release.

"In contrast, nocturnal settling moths — which have many more species than bees — have been neglected by pollination research. Our study highlights an urgent need for them to be included in future agricultural management and conservation strategies to help stem declines, and for more research to understand their unique and vital role as pollinators, including their currently unknown role in crop pollination."