- Author: Kathy Keatley Garvey
It's almost the end of the season for the European wool carder bee, Anthidium manicatum.
A few still hang around the foxgloves, the catmint and the African blue basil in our pollinator garden. They really stand out when they're visiting the hot pink foxgloves (by the way, all parts are poisonous except for the roots), but they're difficult to see when they line up with the African blue basil and the catmint.
Natives of Europe, they were named "carder bees" because the females collect or "card" plant hairs for their nests. The bees, about the size of honey bees, are mostly black and yellow. The females range in body length from 11 to 13 millimeters, while the males are 14 to 17 mm. The males are very territorial as they protect their turf and bodyslam other insects.
These colorful bees were first detected in the United States (New York) in 1963, and first recorded in California (Sunnyvale) in 2007. By 2008, they were well established in the Central Valley, according to Lynn Kimsey, director of the Bohart Museum of Entomology and a UC Davis distinguished professor of entomology. We saw our first one in Vacaville in the spring of 2010.
The bee, according to research entomologist Tom Zavortink of the Bohart Museum of Entomology at UC Davis, was accidentally introduced into New York state. It was not purposefully introduced to pollinate alfalfa, as some reports allege, he said.
Writing in a 2008 edition of the Pan-Pacific Entomologist, Zavortink and fellow entomologist Sandra Shanks, now of Port Townsend, Wash., pointed out that several papers “have documented its spread from neighboring areas in the northeastern United States and southern Canada” and that the species has since crossed the country. It was confirmed in Colorado in 2005, Missouri in 2006, and Maine, Michigan, Maryland and California (Sunnyvale) in 2007, the entomologists wrote. Records show it was first collected in Davis on July 26, 2007.
Its plant preferences include lamb's ear (Stachys byzantine, in the mint family Lamiaceae), a perennial grown for its fuzzy, silvery gray-green foliage. It's also been collected in the figwort/snapdragon family (Scrophulariacae) and the pea and bean family (Fabaceae), according to the Zavortink-Shanks research.
In our yard, they're partial to the foxgloves (shaded) and catmint (full sun). They don't seem to like the lamb's ear (full sun).
They also don't like my camera. The slightest movement, and off they go.




- Author: Kathy Keatley Garvey
Seen any European wool carder bees lately?
European wool carder bees (so named because the female collects or cards plant hairs for their nests) are on the move.
The bees, about the size of honey bees, are mostly black and yellow. The females range in body length from 11 to 13 millimeters, while the males are 14 to 17 mm.
The males are known for being very territorial. They body-slam other insects to protect their turf, per chance to mate with the females.
The European wool carder bees, Anthidium manicatum, are natives of Europe. Their "immigrant ancestor" was first detected in the United States (New York) in 1963, and the species then began spreading west. The bees were first recorded in California (Sunnyvale) in 2007.
The species, according to research entomologist Tom Zavortink of the Bohart Museum of Entomology at UC Davis, was accidentally introduced into New York state. They were not purposefully introduced to pollinate alfalfa, as some reports allege, he said.
Writing in a 2008 edition of the Pan-Pacific Entomologist, Zavortink and fellow entomologist Sandra Shanks, now of Port Townsend, Wash., pointed out that several papers “have documented its spread from neighboring areas in the northeastern United States and southern Canada” and that the species has since crossed the country. It was confirmed in Colorado in 2005, Missouri in 2006, and Maine, Michigan, Maryland and California (Sunnyvale) in 2007, the entomologists wrote. Records show it was first collected in Davis on July 26, 2007.
It was well established in the Central Valley by 2008, according to Lynn Kimsey, director of the Bohart Museum of Entomology and a UC Davis distinguished professor of entomology.
We first encountered the European wool carder bee in Vacaville, Solano County, in the spring of 2010. Its plant preferences include lamb's ear (Stachys byzantine, in the mint family Lamiaceae), a perennial grown for its fuzzy, silvery gray-green foliage. It's also been collected in the figwort/snapdragon family (Scrophulariacae) and the pea and bean family (Fabaceae), according to the Zavortink-Shanks research.
In our pollinator garden, they seem to prefer foxgloves, lamb's ear, catmint and lavender. Yes, in that order...



- Author: Kathy Keatley Garvey
There's a way for a bear to outsmart a fox.
A teddy bear bee, that is.
We just witnessed a male Valley carpenter bee, Xylocopa sonorina, aka "the teddy bear bee," buzz up to a patch of foxgloves, Digitalis purpurea.
Then he engaged in the foraging behavior known as nectar-robbing. That's when a carpenter bee or bumble bee drills a hole at the base of the corolla--or finds a hole already drilled--and "robs" the nectar, bypassing the flower's reproductive parts that lead to pollination.
Hey, I'm not going through the front door! I'm not! I'm taking the back door.
We usually see female Valley carpenter bees drilling the holes and robbing the nectar. This time, though, it was a male. The late Robbin Thorp, UC Davis distinguished emeritus professor of entomology, always referred to the males as "teddy bear bees," adding "boy bees don't sting."
This particular teddy bear lingered a bit, sipped some nectar, and then took flight.
That's how a "bear" outsmarts a fox.
By the way, sexual dimorphism is pronounced in X. sonorina. The male is a green-eyed blond, while the females are solid black.
In our garden, other plants popular for nectar robbing include the salvias, ‘Hot Lips' Sage (Salvia ‘Hot Lips'), and California fuchsia (Epilobium canum). Sometimes you'll see a honey bee following a carpenter bee or bumble bee around to gain easy access to the nectar. She "knows the drill."
Scientists have known about nectar-robbing for more than two centuries. German naturalist Christian Konrad Sprengel observed bumble bees perforating the corollas of flowers as early as 1793, according to Wikipedia. Sprengel recorded this phenomenon in his book, The Secret of Nature in the Form and Fertilization of Flowers Discovered. Charles Darwin observed nectar robbing (by bumble bees) in 1859 and published his observations in his book The Origin of Species.



- Author: Kathy Keatley Garvey
When was the last time you sighted a bumble bee? Photographed it?
It's National Pollinator Week and one of our favorite bumble bees is the yellow-faced bumble bee, Bombus vosnesenskii. It was also a favorite of internationally renowned bee expert Robbin Thorp, distinguished emeritus professor of entomology at the University of California, Davis, who passed away June 7 at age 85. (See obituary)
In fact, all bumble bees were his favorite, including the elusive Franklin's bumble bee, found only in a small range in southern Oregon and northern California and now feared extinct. We remember a July 2010 interview with Thorp:
“People often ask the value of Franklin's bumble bee," Thorp told us. "In terms of a direct contribution to the grand scale of human economies, perhaps not much, but no one has measured its contribution in those terms. However, in the grand scheme of our planet and its environmental values, I would say it is priceless.”
“Loss of a species, especially a pollinator, diminishes our global environment,” he said. “Bumble bees provide an important ecological service--pollination. This service is critical to reproduction of a huge diversity of plants that in turn provide shelter, food (seeds, fruits) to diverse wildlife. The potential cascade of effects from the removal of even one localized pollinator may affect us directly and indirectly.”
Thorp treasured bumble bees and encouraged everyone else to do so, too.
The yellow-faced bumble bees are native to the west coast of North America, from Baja California to British Columbia. They're important pollinators, especially important for their buzz pollination of tomatoes, peppers and cranberries. Buzz pollination occurs when they grab a blossom and shake it, dislodging the pollen. Honey bees can't do that.
The Xerces Society for Invertebrate Conservation recently posted that one quarter (28 percent) of North American bumble bees are in some degree of extinction risk. "Bumble bees face many threats including habitat loss, disease, pesticide use, and climate change." (See more information on bumble bees on the Xerces' site.)
Meanwhile, "across the pond," London has established a seven-mile long bee corridor of wildflowers just for pollinators.
"The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) said wild mammals had declined by 82 per cent since 1980, space for natural ecosystems had halved, and one million species were now at risk of extinction as a result of human action," according to a May 7, 2019 article in The Independent newspaper. "Insect pollinators are vital for the maintenance of ecosystem health and for global food security. Insects are required to maintain the existence of 75 per cent of crop species, 35 per cent of global crop production and up to 88 per cent of flowering plant species," reporter Harry Cockburn wrote.
Want to learn more about the bumble bees around us? A good start is to read these two books, both co-authored by Thorp in his retirement: Bumble Bees of North America: An Identification Guide (Princeton University, 2014) and California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday, 2014).
And, if you would like to get involved in citizen science, Bumble Bee Watch seeks your sightings.


- Author: Kathy Keatley Garvey
Meet the competitors.
In this corner, meet Mr. Teddy Bear. He's a blond, green-eyed carpenter bee, Xylocopa varipuncta, a native, and one of three species of carpenter bees commonly found from northern to southern California to western New Mexico.
In the other corner, meet Mr. Bodyslam. He's a European wool carder bee, Anthidium manicatum, a native of Europe. His "immigrant ancestor" was first detected in the United States (New York) in 1963, and the species spread west. The carder bee (so named because the female "cards" fuzz from plants for her nest) was first recorded in California (Sunnyvale) in 2007.
The competitors meet on foxglove, Digitalis purpurea, which yields dramatic pink-purple fingerlike flowers (and medicine for heart patients).
Mr. Teddy Bear is famished. He's doing what entomologists call "nectar robbing." He's drilling a hole in the corolla and drinking nectar, bypassing the usual plant-pollinator relationship. He's grabbing the reward and "cheating" by entering the flower from the outside, avoiding contact with the anthers.
Mr. Bodyslam is territorial. He's patrolling the foxglove patch--HIS foxglove patch--trying to save the nectar for his own species so he can mate with them. When he sees intruders, he targets them.
So here's Mr. Teddy Bear, drilling and sipping, sipping and drilling. Life is good.
"Hey, get away from my flowers and nobody gets hurt! They're mine!"
"Hey, I'm bigger than you. Get lost."
And the battle begins.
The winner, in this corner, Mr. Teddy Bear. He successfully avoided contact by crawling between the flowers (where Mr. Bodyslam couldn't reach him) and then sneaking to the corolla.
But once--just once--contact erupted. Ouch!





