- Author: Kathy Keatley Garvey
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.
- Author: Kathy Keatley Garvey
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.
- Author: Kathy Keatley Garvey
What a delight to see.
We strolled through milkweed patches in the UC Davis Arboretum Thursday noon and saw them.
Monarchs!
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.
- Author: Kathy Keatley Garvey
All summer and into fall, we spotted the familiar reddish, black and white bugs scurrying around on our showy milkweed, Asclepias speciosa, and tropical milkweed, Asclepias curassavica.
Showy bugs on showy milkweed.
The ones we saw: the Small Milkweed Bug, Lygaeus kalmii. Like its name implies, it's small, about half an inch long.
They're primarily seed eaters, but they're opportunistic and generalists, says insect migration biologist Hugh Dingle, emeritus professor of the UC Davis Department of Entomology and Nematology, author of the popular textbook, Animal Migration: the Biology of Life on the Move. "They'll get protein from wherever they can find it," he said. Dingle, whose research includes migratory monarchs, said the milkweed bugs not only eat seeds, but they also eat monarch eggs and larvae and the immature stages of other butterflies. Forever the opportunists, they eat other small bugs as well--if the opportunity arises. And they feed on nectar, too.
Some scientists have seen them feeding on insects trapped in the sticky pollen of the showy milkweed.
The bugs, it seem, have few predators. They feed on the toxic milkweed, which makes them distasteful to predators, prey to avoid. Their warning colors (red and black) strike home that fact.
In the fall, as the seed pods burst open, it's a horticulture/culinary war between the milkweed growers and the milkweed bugs. Both want the seeds: the humans to plant them and the bugs to eat them.
(Note: Research shows that the milkweed bug also feeds on other plants. Read about the opportunist Small Milkweed Bug in the Journal of the New York Entomological Society.)
- Author: Kathy Keatley Garvey
No, the stuffed turkey didn't slip out of the oven and fall on the floor. Nor did the pumpkin pie turn another shade of orange.
Some unexpected guests arrived--four to be exact.
That's the number of monarch caterpillars we found on our tropical milkweed (Asclepia curassavida) in our pollinator garden in Vacaville, Calif.
Between Nov. 15 and Nov. 24, we've discovered 12 caterpillars on our tropical milkweed, a non-native perennial. (Three other species of milkweed, Asclepias tuberosa, Asclepias speciosa, and Asclepias fascicularis, also thrive in our pollinator garden.)
Just when we thought our small-scale conservation project of rearing and releasing monarchs is all over 'til next year, it's not. Our season total of 54 monarchs is likely to increase.
"This is really far inland for such late breeding," said butterfly expert Art Shapiro, distinguished professor of evolution and ecology who has been studying Central California butterflies for more than four decades and maintains a website on his work and monitoring observations. "Winter breeding has been occurring near the coast for some years now, but I recall no records this late east of the East Bay. October, yes. November? We really need to understand the physiology and genetics of non-repro-diapausing winter monarchs!"
"We've been seeing evidence of a significant fall window of opportunity for larval monarch development for a few years now, which seems different than the historical pattern," noted Louie Yang, associate professor of entomology, UC Davis Department of Entomology and Nematology. "I've wondered if these are returning migrants that are breaking reproductive diapause when they encounter warm conditions in the Valley. I've mostly seen them on late season native milkweeds, but of course the tropical milkweeds are even more persistent."
Meanwhile, the 12 monarchs are the center of attention--well, at least a corner of attention--on our kitchen counter. Our setup: two mesh, zippered containers from the Bohart Museum of Entomology, UC Davis; and four narrow-necked, flat-bottomed bottles filled with water and milkweed stems.
The monarch caterpillars are doing what monarch caterpillars do best--and what folks around the Thanksgiving dinner table do best. Eat.