It's National Pollinator Week. Do you know where your pollinators are?

If you're thinking bees, butterflies, beetles, birds (hummingbirds) and bats, you're correct.

But what about European paper wasps (Polistes dominula)? They're pollinators, too, says associate professor Amy Toth of the Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, who researches wasps and coined the hashtag, #wasplove.

Several years ago she delivered an excellent presentation to our UC Davis Department of Entomomlogy and Nematology, and I later asked her 10 reasons why we should love wasps.

It's worth repeating:

1. They are pollinators.
2. They contribute to biocontrol of lepidopteran pests in gardens and on decorative plants.
3. They have been shown to carry yeasts to winemaking grapes that may be important contributors to the fermentation process and wonderful flavors in wine!
4. They are the only known insect (Polistes fuscatus) that can recognize each other as individuals by their faces.
5. They are devoted mothers that will dote on their young all day long for weeks, defending their families with fury.
6. Their social behavior, in my opinion, is the most human-like of any insect.  They know each other as individuals, and are great cooperators overall, but there is an undercurrent of selfishness to their behavior,
7. They are artists. They make perfect hexagonal nest cells out of paper, which they make themselves out of tree bark + saliva.
8. They are extremely intelligent.  They're predators, architects, good navigators, and great learners.  Among insects, they have large brains, especially the mushroom bodies (learning/memory and cognition area of insect brain).
9. They are beautiful, complex, and fascinating creatures!

That's Amy Toth's list. To that, I'd like to add one more: they are quite photogenic!

The European paper wasp, so named because of its European origin, is relatively new to the United States. Scientists tell us that the P. dominula was not recorded in North America until 1981. P. dominula was first discovered in the United States in the late 1970s near Boston, Mass.  Entomologists worry that it is displacing the native species of Polistes wasps.

Interestingly enough, last year at this time--this very date--European paper wasps were building a nest beneath the overhanging lip of a recycling bin near the Mann lab on the UC Davis campus.

And today they're doing it again. Same place. Same bin. Same spot.

Wrong place. Wrong bin. Wrong spot. It won't be there for long.

A Painted Lady, Vanessa cardui, is often mistaken for a monarch. (Photo by Kathy Keatley Garvey)

The honey bee and the Painted Lady.

Apis mellifera and Vanessa cardui.

They both wanted to sip that sweet nectar from a mustard blossom.

The Painted Lady was there first. Sometimes it's "first come, first served" and sometimes it's "I'll have what she's having."

The persistent bee managed to forage a bit around the blossom, but the butterfly, just as persistent, stayed put.

Finally, the bee buzzed over the butterfly, nearly touching it, as it headed for new territory.

Meanwhile, the cardui migration continues, from California through the Pacific Northwest. Millions have already moved through the Davis/Sacramento area on their way up north.

"It's Week 11, Day 81," says butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology. "It's almost over (through this area)."

An article published May 19 in the Idaho Statesman, Boise, announced that "Hundreds of Butterflies Flitted Through Boise This Weekend."

"This weekend, Boiseans found themselves in the middle of a massive migration as hundreds of orange-and-brown butterflies known as painted ladies winged their way through the area," wrote reporter Nicole Blanchard. "Dozens of people on social media shared accounts of seeing the butterflies flying overhead en masse or stopping to snack on spring blooms. Many of the painted lady butterflies, which are often mistaken for monarchs because of their orange coloring, were spotted in the North End and Foothills on Saturday."

One Boise resident related on Twitter that she saw 56 flying northwest through her yard in a period of two minutes.

Want to learn more about Painted Ladies and other butterflies? Check out Art Shapiro's website. He's been monitoring the butterfly populations of Central California since 1972.

On Vanessa  carduii: The mass migration begins near the U.S.-Mexico border, Shapiro says. They breed "in the desert after the winter rains generate a crop of annual Malvaceous, Boraginaceous and Asteraceous hosts. The resulting butterflies migrate north. In good years (lots of desert rain) they may do so by billions, interfering with traffic and attracting the attention of the media. 2005 was one of the biggest Painted Lady years in history--perhaps the biggest," he says. This year was also a very good year.

"They do not stop to feed or have sex until they have burned up their reserves, carried over from the caterpillar stage," according to Shapiro. "They fly in a straight line from SE to NW, like 'bats out of Hell,' and go over obstacles rather than trying to go around them. (On certain days there may be concerted local movements in the wrong direction. We do not understand these.) Painted Ladies tend to fly parallel to the Sierra Nevada, not across it. They enter the Central Valley through the Inyo-Kern lowland or by crossing the Transverse Ranges. They can apparently make it from Bishop to Davis in three days. In some years the migration is heavier in the Great Basin and on the East slope of the Sierra than farther west. The Painted Lady moves northward in a generational wave as the season progresses. Frequently it disappears altogether from the lowlands in summer. Beginning in August the movement reverses and butterflies head south toward the desert wintering grounds. The southward migration is a more protracted affair, with plenty of adult feeding and some breeding en route. Numbers tend to be highest east of the crest, on Rabbitbrush blossoms in October."

It's been a very good year for these orange-black butterflies, which began arriving in the Davis/Sacramento area on March 17. Just don't confuse them with Monarchs! Shapiro can't begin to count the calls of folks telling him that the Monarch is no longer in trouble; that "there are millions of them!"

Scientist-artist Karissa Merritt. (Photo by Kathy Keatley Garvey)

The gift shop is offering a selection of insect-themed T-shirts, in both adult and children's sizes, for $10, and the Bohart-produced 2019 calendars for $8.

Lynn Kimsey, director of the museum and UC Davis professor of entomology, says that "we have adult sizes in the clubtail and pondhawk dragonfly and dog-faced butterfly designs, and a variety of children's t-shirts."

The calendar?

It's a fun and innovative calendar, with art by UC Davis entomology student/artist Karissa Merritt, based on sentence collections from Kimsey's classrooms. Kimsey collects puzzling or humorous sentences ("What's that again?") written by her students.  The calendar is a project of the non-profit Bohart Museum Society.

The Bohart Museum, home of nearly eight million insect specimens, also maintains a live "petting zoo," comprised of Madagascar hissing cockroaches, walking sticks and tarantulas.

The Bohart, located in Room 1124 of the Academic Surge Building on Crocker Lane, is open to the public Monday through Thursday from 9 a.m. to noon and from 1 to 5 p.m. (More information is available on the website or by contacting bmuseum@ucdavis.edu or  (530) 753-0493.) 

In between the rains today, we saw them.

So beautiful!  Painted ladies, Vanessa cardui, nectaring in patches of colorful wildflowers in the Biological Orchard and Gardens (BOG), located behind the Mann Laboratory on University of California, Davis campus.

The migratory butterflies, passing through California on their way to the Pacific Northwest, stopped there for some flight fuel: sipping nectar from tidy tips, Layia platyglossa; five-spot, Nemophila maculate, and blue lupine, Lupinus.

They've been in the national news a lot, these butterflies, as has butterfly guru Art Shapiro, UC Davis distinguished professor of evolution and ecology. Known for his expertise on all things butterfly, he's monitored the butterfly population of Central California since 1972 and maintains a research website.

Yes, it's been a big year for painted ladies, thanks to the heavy rainfall and super blooms in the deserts near the Mexican border.  And, as Shapiro says, tremendous wildflower blooms are typically great years for the painted ladies.

New York Times reporter Julia Jacobs interviewed Shapiro for her March 17th piece, in which she marveled that millions of the painted ladies are migrating. Shapiro told her: "The striking thing is they're moving very rapidly and directionallly. So it's almost like being in a hail of bullets.”

Rita LeRoy or "Farmer Rita," the self-described "Farm Keeper" on the Loma Vista Farm, Vallejo, part of the Vallejo City Unified School District, saw the butterflies passing through the farm on Monday, March 17. Her description is fabulous:

"They came through Vallejo on Monday," she said. "Art's description was right on. It was like being in a hail of bullets. This was because they were flying so low and it was a constant stream, like standing in the middle of a 500 lane expressway. I kept telling the students, 'Look! Another, another, another...' The path was at least as wide as the farm which is about 200 yards. When I stood in one spot, I would agree they were passing within my vision (about 100') at about 1 every second. They rarely stopped to nectar but were flying in a very direct NE direction when they came through the farm. They flew through nonstop from before 1 p.m. and the flow started to dwindle around 4 p.m. Still enough at that point to show the after school kids. They didn't fly in huddled groups or clouds and they moved fast. I tried taking a video but it was like a bad remake of The Blair Witch Project, with unfocused, whiplash camera moves of uncertain objects since they are so small in the overall background. I'm so glad Art saw them."

Today (Wednesday) we didn't see the hail of bullets, but we did see about a dozen of them grabbing some flight fuel on the UC Davis campus over a 10-minute period.

If you get a chance, check out the Biological Orchard and Gardens. A 24,000-square-foot garden, located behind the Mann lab, off Kleiber Hall Drive, it's planted with several dozen species of heritage fruit trees, and landscaped with flower gardens. The painted ladies are elsewhere on campus, too, including the UC Davis Arboretum and Public Garden.