Photo: Juniper Hairstreak on Fleabane, Judy Gallagher
Judy Gallagher
February 2025
I'm looking out my window at freshly fallen snow, trying to appreciate the season. But my thoughts keep wandering to spring, and right now I'm dreaming of butterflies fluttering erratically from flower to flower.
Ocola Skipper with pollen on its face, Judy Gallagher
When a butterfly lands on a flower to drink nectar, pollen sometimes rubs off on the butterfly. The pollen may be transferred as it visits other flowers. We usually think of bees as our key pollinators. But although they lack specialized structures for collecting pollen, butterflies and their moth cousins are also pollinators.
Juniper Hairstreak on Fleabane, with pollen on its abdomen and proboscis, Judy Gallagher
Butterflies like flowers with a landing platform, perhaps a daisy or fleabane, and they gather pollen as they wander around the flower clusters. They may not be as efficient pollinators as bees, but they visit an amazing number of flowers each day. Scientific studies have shown that butterflies like nectar with lots of amino acids, which appears to help them lay more eggs. They like brightly colored flowers, and unlike most bees, butterflies can see red. Many sense odors through chemoreceptors in their antennae, and so can smell sweet floral scents from a distance. Butterflies tend to fly farther than bees, and can potentially pollinate a larger area than bees.
Common Buckeye with Milkweed pollinia stuck to its foot, Judy Gallagher
Milkweed flowers are unusual in that their pollination structures and pollen are hidden inside the flower. The only way an insect can get to the pollen is to accidentally get its foot stuck inside the flower. When it extracts its foot, a mass of pollen grains called a pollinia may be attached, shown here (above and below) on a Common Buckeye.
Common Buckeye with pollinia detail , Judy Gallagher
Here's a closer look, above, at the Common Buckeye's feet. The pollinia are the yellow, elongated structures. Pollination occurs if the butterfly gets its foot with attached pollinia stuck in a different milkweed flower.
Great Spangled Fritillary on Flame Azalea with pollen on its wings, Judy Gallagher
Butterflies are the most important pollinator of Flame Azaleas. The anthers and stigmas of flame azalea flowers are widely separated, and large butterflies like Great Spangled Fritillaries and Eastern Tiger Swallowtails have wings that brush against the flowers, thereby collecting or depositing pollen. Scientists designed experiments to see how effective the butterflies were as Flame Azalea pollinators. When all pollinators were prevented from pollinating, or all pollinators except butterflies were allowed to pollinate, pollination rates were very low. When the butterflies were allowed in, pollination rates were ten times higher.
Eastern Tiger Swallowtail on Tiger Lily, Judy Gallagher
Butterfly wings can also pollinate Tiger Lilies, as this Eastern Tiger Swallowtail is demonstrating above.
Butterflies pollinate some commercial crops. They are the primary pollinators of Macadamia Nut trees in Brazil. They also can pollinate cotton. In a recent study, scientists catalogued the insects that visited cotton flowers. There were 40 bee species, 16 fly species and 18 butterfly species. Bees tended to visit the inner flowers, and flies and butterflies landed on outer flowers. This meant that 50% more flowers were visited than if bees were the only pollinators, and flies and butterflies were responsible for about one third of the pollination.
Butterfly with pollen on its face and eyes, Judy Gallagher
Here's an extreme close-up of a butterfly's head. Note the pollen grains scattered through its scales, and there are even a couple of grains on its eye. Do you know what popular butterfly this is?
I thought about not giving you the answer until next month's column, but leaving you in suspense would be cruel. Plus, I might forget by next month that I had promised to give you the answer. This pollinator is a Monarch.
Spring will be here before long. I hope you can spend quality time appreciating our butterfly pollinators.
View more of Judy’s Closer Look (formerly Observations from Meadowood) articles here.