"More than beautiful, monarch butterflies contribute to the health of our planet. While feeding on nectar, they pollinate many types of wildflowers.--National Park Service.
Have you ever seen pollen on a monarch butterfly?
This morning a male migrating monarch, probably on its way to coastal California to an overwintering site, stopped at a Vacaville garden to sip some nectar on a Mexican sunflower (Tithonia rotundifola).
If you look closely, you can see the gold pollen.
Monarchs are not just iconic species facing a population decline, they're pollinators.
"Pollinator species, such as bees, other insects, birds and bats play a critical role in producing more than 100 crops grown in the United States," according to the U.S. Department of Agriculture. "Honey bee pollination alone adds more than $18 billion in value to agricultural crops annually."
The late Argentine-born biologist Beatriz Moisset (1934-2022) of Willow Grove, Pa., called the insect "A Pollinator with a Bad Reputation."
Moisset, who received her doctorate from the University of Cordoba, Argentina, and authored the book, Bee Basics, an Introduction to Our Native Bees, was referring to bee flies, from the family Bombyliidae. In their larval stage, these flies parasitize the eggs and larvae of ground-nesting bees, beetles, and wasps.
They superficially resemble bees. If you look closely, however, they have one-pair of wings (bees have two pairs), and their antennae are short and stubby, unlike that of bees.
They neither bite nor sting. Bombyliidae includes some 4500 described species, found throughout North America, Europe and Asia, with many more undescribed.
If you see these long-legged, fuzzy-looking insects, they're usually foraging on flowers or hovering above the ground.
"The reason why it diligently hovers over bare ground early in the spring is that it is looking for bee nests," Moisset wrote in a piece published on the U.S. Forest Service website. "The bees dig tunnels and lay their eggs at their bottoms after collecting enough pollen to feed the larvae. This requires numerous trips, thus the bee fly takes advantage of the mother's absence and lays its eggs in such nests. Making use of its flying prowess, it does not even need to land but it flicks its abdomen while hovering over the open burrow, letting one egg fall in or near it."
"The fly larva finds its way to the chamber where the mother bee has laid the provisions and the egg and proceeds to feed on the stored pollen," Moisset explained. "Afterwards it devours the bee larvae; when it is fully grown, it pupates and stays inside the nest until next spring."
We spotted a bee fly in a Vacaville pollinator on Sept. 19. It zoomed over a yellow zinnia, hovered, and then dropped down to sip some nectar. Meanwhile, looking like a cross between a bee and a fly, it skirted syrphid flies and honey bees also intent on getting their share of nectar.
The bee fly is aptly named.
They are a beautiful sight.
Hopefully, tagged migratory monarchs from the research project of entomologist David James of Washington State University, will pass through--as they do every year from the Pacific Northwest--on their way to their coastal California overwintering sites. They are tagged on a discal cell.
Meanwhile, scientists in the Northeast are tagging monarchs (heading for Mexico) in a different way. They're attaching "small, lightweight tracking devices to nearly 50 strong and healthy butterflies," according to the New Hampshire Public Radio, in a piece published Sept. 12. "Towers can then ping their location when the small creatures are nearby."
The article related that "Scientists across the country are studying their migration patterns through a project funded by the federal government. This is the second full year that the New Hampshire Audubon Center is participating in a monarch tracking program."
The article by Olivia Richardson quotes Diane De Luca who works at the center: “The thought behind tagging monarchs here in the Northeast is to get a better sense of what they actually do when they're first starting their migration."
The tracking devices are lightweight, but the scientists seek out "strong, younger butterflies" without tattered wings. (See more on the website)
One tracked butterfly flew 60 miles in one day.
"De Luca said last year a butterfly they tagged traveled to Massachusetts and stopped at Lynnfield Marsh, one of the state's largest freshwater marshes," Richardson wrote. "De Luca said purple loosestrife, a type of flower considered an invasive species, is abundant at the marsh and it's attractive to monarch butterflies, who feed off of it."
Aren't monarchs fascinating?
Ping! There goes another butterfly!
So here's this male monarch nectaring on a pink zinnia in a Vacaville pollinator garden.
The nectar is rich and he is as hungry as a migrant butterfly seeking flight fuel for the long journey ahead.
A painted lady, Vanessa cardui, apparently in an amorous mood, quickly approaches and touches down next to him.
Monarch: "Whoa! What's going on?"
Painted lady: "Oops! Wrong species, wrong gender. Sorry about that! I'm leaving!"
Monarch, spreading his wings and preparing to leave: "That makes two of us!"
If you live in California, tagged monarchs from the migratory research project of entomologist David James of Washington State University may be heading your way.
One tagged monarch, a male, fluttered into our Vacaville pollinator garden on Sept. 5, 2016. Citizen scientist Steven Johnson of Ashland, Ore., tagged and released it on Aug. 28. It nectared on Mexican sunflowers (Tithonia rotundifola) and a butterfly bush (Buddleia davidii) before heading to an overwintering site in coastal California.
The tag read “Monarch@wsu.edu A6093.”
James later told us: "So, assuming it didn't travel much on the day you saw it, it flew 285 miles in 7 days or about 40.7 miles per day. Pretty amazing."
If you see a tagged monarch ("quite a few are being tagged in southern Oregon," James says), try to take an image. Then detail the information (where spotted and when) and send it to the WSU entomologist at firstname.lastname@example.org. Read more on his Facebook page, Monarch Butterfies in the Pacific Northwest.
Meanwhile, we've been seeing monarchs daily in our garden since late August. We spotted one monarch laying eggs on our tropical milkweed, Asclepias curassavica, on Aug. 10. (That was her choice of milkweed: she ignored the narrow-leafed milkweed, A. fascicularis; the showy milkweed, A. speciosa; and the butterfly weed, A. tuberosa.)
On Sept. 5, two monarchs, a male and a female, eclosed, while a male monarch patrolled overhead. The newcomers dried their wings and fluttered off. Both managed to escape several predators: Western scrub jays, praying mantises, and assorted crab spiders.
Welcome to the world!