Migrating monarchs are fluttering daily into our yard in Vacaville, Calif., one by one, two by two, three by three, and four by four, for a little flight fuel. They're sipping nectar from the Mexican sunflower, Tithonia rotundifolia, and tropical milkweed, Asclepias curassavica.
They're on their way to overwintering sites, such as the Natural Bridges State Park's Monarch Grove Butterfly Natural Preserve, Santa Cruz.
The park's monarch sanctuary "provides a temporary home for thousands of monarchs," according to the website. "In 2016, 8,000 monarch butterflies overwintered at Natural Bridges. From late fall into winter, the monarchs form a 'city in the trees.' The area's mild seaside climate and eucalyptus grove provide a safe place for monarchs to roost until spring."
The numbers typically peak between late October to mid-November. It's an awe-inspiring place, especially if you rear monarchs. And admission is free. The preserve is open to the public from 8 a.m. to sunset daily, or visitors can participate in a free one-hour tour on Saturdays and Sundays at 11 a.m. to 2 p.m.
Meanwhile, scores of monarchs are on their way. Some won't make it. Predators, especially birds, will nail many of them. The weather will deter many others.
We know of at least one that probably won't make it. On Friday, Oct. 27, while we were gathering mllkweed seeds from the Asclepias curassavica, we noticed two lady beetles feasting on aphids.
Wait, what's that beneath that leaf?
Could it be? It was. A monarch caterpillar! Talk about late!
The 'cat is now tucked inside our indoor butterfly habitat, munching on milkweed leaves. With any luck, it will become a mid-life chrysalis and then an adult monarch.
It will take a lot of luck, however, for it to join its buddies in Santa Cruz. Its late start will be exacerbated by the cold, the wind, the rain, the predators....
On a wing and a prayer...
A partial solar eclipse is about to happen in Vacaville, Calif.
I am watching the insects: the honey bees nectaring on the African blue basil, an orbweaver spider munching on its prey, an assassin bug poised on a tropical milkweed, and a praying mantis lurking beneath a showy milkweed leaf.
Today (Aug. 21) is the long-awaited Great American Eclipse. The totality path will begin at 9 a.m. in Oregon, and stretch across the country to South Carolina.
Hmm, I wonder, how will the bugs in our pollinator garden react to a partial eclipse?
It won't be drastic, I predict. And it wasn't.
The partial eclipse in Vacaville began at 9:02 a.m. and reached its maximum (70 percent coverage of the sun) at 10:16. It ended at 11:38 am., a duration of two hours and 36 minutes.
The bees foraged before, during and after the eclipse, primarily on the African blue basil, which is usually covered with bees. During the height of the eclipse, however, as the skies darkened, a little more than half remained. After the eclipse, when the temperature increased and the wind ceased, the number of bees returned to normal.
"Honey bees tend to act like night is falling if the eclipse takes out quite a bit of the sunlight," says honey bee guru Eric Mussen, Extension apiculturist emeritus and president of the Western Apicultural Society. "Then they 'wake back up' afterwards."
Despite the eclipse, the spider kept eating its prey. (Sure hope it wasn't that blue dragonfly, Libellula luctuosa, "the widow skimmer" I saw yesterday.) The praying mantis kept lurking. The assassin bug raised its antennae. And the bees--although fewer of them--just kept foraging.
Two stink bugs opted to procreate on the bluebeard, Caryopteris x clandonensis. A Gulf Fritillary fluttered by and stopped to sip nectar from the Mexican sunflower (Tithonia). The assassin bug crawled higher on the milkweed, poised for an ambush.
The spider tugged its prey beneath a leaf, abandoning its web. Well, that's that, I thought.
Not so. The sticky web snagged a honey bee while the spider was polishing off its first prey. Okay, spider, you've already had your breakfast. You don't need a second helping. Not today."
I freed the struggling bee and off it buzzed to forage another day.
A partial eclipse, but a full escape...
A fly, oh, my!
On the approval scale, they don't rank nearly as high as honey bees, but some are often mistaken for them.
Take the Eristalis stipator, which belongs to the family Syrphidae, the hover flies.
It's about the same size as a honey bee and it's a pollinator.
We recently spotted this one--a female Eristalis stipator, as identified by senior insect biosystematist Martin Hauser of the California Department of Food and Agriculture--nectaring on tropical milkweed, Asclepias curassavica. The colors are striking--both the colors of the fly and the flowers. It's a striped fly, with black and white bands, one superimposed gold band, and buff-colored hairs piled on the thorax. And the showy flower, aka "blood flower," is red-orange with a yellow hood.
Eristalis is a large genus of approximately 99 species. The Eristalis stipator has no common name, so we just call it Eristalis stipator.
Or a fly.
In real life, insects "get" milkweed.
We all know it's the only host plant of the monarch butterfly--where monarchs lay their eggs--but it's also a a great source of nectar for butterflies and other insects.
Take the showy milkweed, Asclepias speciosa. Native to California, it is found throughout North America, including in our little pollinator garden!
Speciosa nectar is sweet, tantalizing and irresistible.
Recently we've been watching the diversity of insects gathering on our milkweed. Sometimes it's a pushing/shoving match or I'll-fly-away-but-I'll-be-back-as-soon-as-you-leave vow.
Have you ever seen a male Valley carpenter bee, Xylocopa varipuncta, nectaring on milkweed? The male, a green-eyed blond about the size of a queen bumble bee, can't sting. Or as native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at UC Davis says--"Boy bees can't sting." He calls it "the teddy bear bee." What could be more cuddly than this little fellow?
So here's this teddy bear bee trying to grab some nectar while honey bees are buzzing around him trying to get their share. He's bigger; they're louder.
And then, the female of this Valley carpenter bee species (she's solid black--the two represent a clear case of sexual dimorphism) comes along and the bees scatter. Our boy bee does, too.
The bees will be back. The nectar is sweet, tantalizing and irresistible.
What a delight to see.
We strolled through milkweed patches in the UC Davis Arboretum Thursday noon and saw them.
The monarch butterflies (Danaus plexippus) are returning from their coastal California overwintering sites. And we're getting new generations.
The UC Davis campus, including the 100-acre UC Davis Arboretum is home to much celebrated flora and fauna, including milkweed and monarchs.
After overwintering along the California coast and in central Mexico, the butterflies flutter north into the United States and Canada in the spring and summer.
However, scientists report that the monarch population in central Mexico declined from 100 million last year to 78 million this year, due to late winter storms, coupled with cold and wet weather, and deforestration.
It's a sure sign of spring, through, when the monarchs return. It's a cause for celebration. Welcome back!
Meanwhile, we're anticipating the arrival of Christine Merlin, assistant professor in Texas A&M's Department of Biology, who will discuss her research on "The Monarch Butterfly Circadian Clock: from Clockwork Mechanisms to Control of Seasonal Migration" when she presents a seminar on Wednesday afternoon, May 31 at the University of California, Davis. The seminar is set from 4:10 p.m. to 5 p.m. in Room 122 of Briggs Hall. Host is molecular geneticist Joanna Chiu, associate professor and vice chair of the UC Davis Department of Entomology and Nematology.