- Author: Kathy Keatley Garvey
"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."
- Author: Kathy Keatley Garvey
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 monarch@wsu.edu. 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!
- Author: Kathy Keatley Garvey
And just like that, a female monarch butterfly fluttered into our Vacaville pollinator garden this morning, Aug. 10, and left a dozen or so calling cards: precious eggs.
We earlier saw a male monarch patrolling the garden on the morning of July 23, but he left to go find the girls.
So, total number of monarchs sighted in our garden so far this year: 2. (In 2016, we counted more than 300 eggs and caterpillars.)
Ms. Monarch deposited eggs on three milkweed plants: a narrow-leafed milkweed, Asclepias fascicularis, and two tropical milkweeds, Asclepias curassavica. She favored a lone tropical milkweed thriving in a planter. It's already attracted honey bees, leafcutter bees, syrphid flies, crab spiders, cabbage white butterflies, Gulf Fritillaries, mourning cloaks, gray hairstreaks, Western tiger swallowtails, ants, aphids, and a young praying mantis lying in wait.
Ms. Monarch totally ignored the showy milkweed, Asclepias speciosa, that towers over the garden. Not for me, she seemed to say. Ditto on the butterflyweed, Asclepias tuberosa.
We managed a few images of Ms. Monarch in flight, several images of her laying eggs, and a couple of the ever-so tiny eggs clinging beneath the leaves.
Welcome, Ms. Monarch. Now go tell all your buddies where to find the milkweed of your choice, and the rich nectar sources such as Mexican sunflowers (Tithonia rotunifola).
And you better warn them about that praying mantis...
- Author: Kathy Keatley Garvey
Apparently so, from personal observation.
Over the years, we've grown multiple species of milkweed in our pollinator garden in Vacaville, Calif. We give them a choice. The species include:
- Narrow-leafed milkweed, Asclepias fascicularis
- Showy milkweed, A. speciosa
- Pleurisy root, A. tuberosa
- Tropical milkweed, A. curassavica
- Hairy balls or balloonplant, Gomphocarpus physocarpus
Which species do they prefer? Tropical milkweed, hands down. But it's a plant that's become highly controversial in California. Friends unfriend friends, and the unfriended lash out with how "bad" tropical milkweed is and how "uneducated" the messenger is. "Don't you know about Ophryocystis elektroscirrha (OE)?" they ask. "How dare you plant tropical milkweed? Yank it out!"
Meanwhile, the monarchs keep monarching. And we keep observing them.
Consider the male monarch spotted lying in the middle of a residential street in west Vacaville the morning of Jan. 3. It was there despite the rain, the cold and the passing cars. What will happen to it? Will it find a mate? Will its mate be able to find a milkweed to deposit her eggs? She certainly won't find native milkweed, such as A. fascicularis and A. speciosa, but she might find A. curassavica.
If. She. Is. Lucky.
Mona Miller, administrator of the educational Facebook page, Creating Habitat for Butterflies, Moths and Pollinators, recently shared a post that should be "food for thought" (for us) and that should result in "more food" (milkweed) for the monarchs. Her Facebook page focuses on "the preservation and protection of North American butterflies, moths and pollinators, particularly the Monarch butterfly."
"All milkweeds get Ophryocystis elektroscirrha (OE)," Miller wrote. "There are native milkweeds that are viable in the fall and winter. Tropical milkweed, due to their high level of toxins (cardenolides), are very medicinal. Monarch females choose tropical milkweeds over less toxic native plants to self-medicate. In October 2022, there was a discussion on the Monarch Watch email list. Dr. (Orley "Chip") Taylor (founder and director of Monarch Watch and a professor in the Department of Ecology and Evolutionary Biology at the University of Kansas) said that tropical milkweed does not stop the migration. He said more native and tropical milkweed should be planted. He said the more milkweed that is available the less spores will be left on all milkweeds. Fewer milkweeds leave monarchs visiting available milkweeds and leaving more spores. You can read the discussion here, there are several posts: https://lists.ku.edu/pip.../dplex-l/2022-October/012192.html."
"Actually, the best strategy is to plant more milkweeds, both native and tropical," Professor Taylor wrote, explaining that "First, the interactions between monarchs, milkweed and O.E. are frequency and density dependent. What this means is that spore loads on foliage are dependent on the abundance of milkweed relative to the number of ovipositing females. The O.E. infection rate is a function of this dynamic. Second, because of these relationships, O.E. cycles. That is, it increases and then declines only to increase again. There is a seasonal pattern to these cycles with low rates in the spring and higher rates about 3-4 generations. Third, the interactions that contribute to cycling involve spatial relationships that include distances between resources (milkweed patches) and the search capabilities of the butterflies. There is a time component as well."
"Here is the scenario that could play out from San Diego to Ventura counties and parts of Marin as well," Taylor wrote. "Due to warmer conditions more and more native milkweeds (mostly fascicularis) remain green during the winter. This appears to be happening over a broad area. With the sale of tropical milkweed (hereafter TM) being prohibited and homeowners being discouraged from growing TM, what is the likely outcome? With fewer milkweeds overall, the O.E. spore count will go up on both native and TM. OE will become more common rather than less. Further, the reduced distribution of milkweeds will reduce the opportunity for O.E. to cycle. Cycling depends on part of the milkweed distribution being relatively free of spores for the monarch population to recover. Overall, there will be fewer butterflies surviving the winter and therefore a lower starting population in the spring. If that happens, there will be fewer monarchs through the entire season. So, instead of leading to lower O.E. and more butterflies, the elimination of TM is likely to reduce the monarch population--in effect taking the butterflies away from the people. Again, in addition to cutting back TM from time to time to reduce O.E., an alternative solution is to grow TM and to see that it is hyper-dispersed in gardens, etc. through the 5-county area. The same strategy would involve A. fascicularis and other native milkweeds."
"Some of the reaction to TM is simply based on the notion that it is non-native," Taylor wrote. "We can agree on that point. However, it does not naturalize and therefore is not invasive. Our gardens are filled with such plants. TM supports populations of monarchs as far south as Peru and in most, if not all, places where monarchs have been introduced. Also, since this species flowers nearly continuously through the growing season, it is a source of nectar for a large number of pollinating species. TM supports monarchs--full stop! Let's learn to live with it. More milkweeds equal more monarchs and less O.E. overall."
Taylor went on to say that TM does not cause monarchs to break diapause and become reproductive. "Dingle suggests that it is temperature that causes monarchs to break diapause and that is exactly what I have been saying for years. Hormone production is a function of temperature--head temperatures--and not contact with plants. The major driver in the West has been and will continue to be weather/climate. It starts with the conditions that determine the size and distribution of the overwintering female numbers and their reproductive success."
However, the California Department of Food and Agriculture (CDFA), influenced by conservation groups, has categorized A. curassavica as "a noxious weed," and county agricultural commissioners have banned the sale of the plant in nurseries in Marin, Contra Costa, San Mateo and Ventura counties.
Professor Dingle bears to differ. "No one should rush out and pull out their tropical milkweed as it would be a waste of time and effort," he says. "Nurseries should also be able to continue to sell it." He points out:
- "There is not enough tropical milkweed planted to have much influence (see the amount of A. syriaca and A. fascicularis throughout the American west not to mention various other species like A. erosa, cordifolia, californica, etc.) Yes, there are parasites on A. curassavica as there are on ALL milkweeds."
- "There are populations of monarchs that are doing just fine feeding exclusively on A. curassavica (e.g. on many Pacific Islands, such as Guam where I have studied them.
- "Migration and the diapause that accompanies it in the fall are determined by shortening photoperiod and temperature (warm temps can override short days hence the issue with climate change). There is no significant influence of food plant."
UC Davis distinguished professor Art Shapiro, who has monitored butterfly populations in central California since 1972, says the "anti-curassavica propaganda is total hogwash. I have been saying so for years."
Curious, isn't it, that a plant can be so controversial? Four states, California, Arizona, New Mexico and Texas, border Mexico. On the California side, inches away from the Mexican border, tropical milkweed is considered a "noxious weed" per the CDFA definition. On the other side, in Mexico, it's simply a great host plant for monarchs.
What does 2023 hold for the iconic monarch and its host plants? For one thing, more scientific research is needed.
- Author: Kathy Keatley Garvey
It looked newly emerged but it wasn't moving.
In fact, it looked quite dead.
A gloved hand quickly rescued the monarch, a male, from passing traffic.
A monarch in January? Here in Vacaville after heavy rain and flooding and more on the way? "A third atmospheric river storm," National Public Radio (NPR) announced Jan. 2, "is set to add to misery in California's flooded areas. Forecasters in Northern California have a sobering new-year message for people who are reeling from floods and mudslides: the situation could get worse before it gets better."
"Much like the end of 2022 storm, this will be a strong wind event along with moderate to heavy rainfall," according to the National Weather Service.
Rain, floods, and recent freezing temperatures....
So how incredible to find a monarch here in January, while its "clan" is clustering in overwintering spots along the California coast. (They won't be heading inward until around February.)
"How long has it been seen you saw Monarchs flying in your area?" asked Mona Miller, who administers the popular Facebook page, Creating Habitat For Butterflies, Moths, & Pollinators. "Another option is that if it found a microclimate, which protected its cycle it has been slowly finishing its cycle. With climate change and fluctuating temperatures, I have been seeing late Monarchs surviving several frosts. Once they make it to adults, fall to winter Monarchs become more cold tolerant. This cold tolerance is rapid and protects them from fluctuating temperatures caused by climate change."
The last monarch I saw flying in Vacaville was on Oct. 26, 2022. It was a male that stopped to nectar on our Mexican sunflower (Tithonia rotundifola). The blooms are long gone. We're in the dead of winter.
But there's hope.
"The ongoing wild windy wet weather in California is the wild card that interferes with predictions about the summer population in 2023," James commented. "Wild late winter storms are likely what caused the substantial reduction (from ~ 200,000 to 30,000) in western monarch numbers back in 2018/19. These lower numbers then led to the ultra-low number in 2020 of 1899 overwintering butterflies. Then of course we rebounded to more than 247,000 in 2021 and likely more than 300,000 for Nov 2022."
"The question now," James said, "is will the current storms and any others that occur during January-February, savagely dent the population as the 2018 storms did? If the overwintering population can survive the storms without major losses, then I think we will see a good-sized summer population in California and the Pacific Northwest in 2023." He administers the Facebook page, Monarch Butterflies in the Pacific Northwest.
It's sponsored by the Western Monarch Advocates (WMA) and is open to all interested persons--from scientists to citizen scientists to monarch aficionados. It will include networking, field trips, and meals.
James, a WMA board member, will be among the keynote speakers from four countries. The event is billed as "an exchange of ideas from across the Western States, Tribal Lands, Mexico, Canada and Australia-all with an interest in our western monarch population! Expand your knowledge and make connections with other Monarch enthusiasts, researchers, and conservation organizations."
As they point out, "our migrating Western Monarch butterflies do not stop at state or international borders; nor should our efforts to restore them."
And, apparently, the Vacaville monarch lying cold and still on a residential street on Jan. 3 didn't let the rain, the storm and the floods--or passing cars--stop him from surviving. He also avoided the hungry birds seeking a fast-food meal (birds learn quickly that monarchs "don't taste good").
He's alive.
Monarchs continue to inspire and surprise us.
