Posts Tagged: Robbin Thorp
Mother's Day, insect-style, dawned like any other day. In our back yard, golden honey bees foraged in the lavender and those ever-so-tiny sweat bees visited the rock purslane.
The honey bees? Those gorgeous Italians.
The sweat bees? Genus Lasioglossum, as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis. He figures the female sweat bee (below) may be L. mellipes, which is brownish toward the tips of the hind legs.
A trip to Benicia yielded a photo of a ladybug chasing aphids. It was almost comical. A fat aphid appeared to be playing "King of the Hill" while other aphids sucked contentedly on plant juices, unaware of pending predators.
While the aphids wreaked havoc on a very stressed Escallonia (fast-growing hedge in the family Escalloniaceae), the ladybugs, aka lady beetles, wreaked havoc on some very stressed aphids.
After all, "stressed" spelled backwards is "desserts."
Italian honey bee foraging on lavender. (Photo by Kathy Keatley Garvey)
Sweat bee (genus Lasioglossum) visiting rock purslane. (Photo by Kathy Keatley Garvey)
Ladybug, aka lady beetle, chasing aphids. (Photo by Kathy Keatley Garvey)
"Just wanna be your teddy bear..."
When Elvis Presley sang that, his fans swooned.
Well, there are bee fans that can't get enough of the "teddy bear" bee, aka the male Valley carpenter bee (Xylocopa varipuncta).
It's often called a "golden bumble bee." Golden, it is. Bumble bee, it is not.
The female of this carpenter bee species is solid black.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, spotted this male Valley carpenter bee yesterday in the Häagen-Dazs Honey Bee Haven, Harry H. Laidlaw Jr. Honey Bee Research at UC Davis. He does research in the half-acre bee friendly garden. (By the way, it's located on Bee Biology Road, west of the central campus, and is open from dawn to dusk. There's no admission.)
We at UC Davis periodically receive phone calls about "golden bumble bees." The green-eyed, golden-haired carpenter bee does attract a lot of attention.
"Oh, let me be, your teddy bear."
Or better yet, let me "bee" your teddy bear.
Honey bee and male carpenter bee (Xylocopa varipuncta) on tower of jewels (Echium wildpretii). (Photo by Kathy Keatley Garvey)
Close-up of the male Valley carpenter bee (Xylocopa varipuncta) on tower of jewels (Echium wildpretii). (Photo by Kathy Keatley Garvey)
If you visit the Jepson Prairie Reserve near Vacaville-Dixon in Solano County, keep your eyes out for Andrena (mining) bees on the meadowfoam (Limnanthes).
We were out there Monday morning and saw a mining bee nestled inside a white flower cup. The bee, about the size of a grain of rice, wasn't moving.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis, and a noted expert on "Vernal Pool Flowers and their Specialist Pollinators," identified the bee below as a male Andrena (mining bee) and "most certainly Andrena pulvera, the species whose females specialize on Limnanthes as their pollen source."
The males have no burrows. "They spend the night inside the meadowfoam flower cups so they are frequently encountered as 'sleeping' inside them early in the morning. As soon as the sun warms them up, they go about their business searching for meadowfoam patches for females."
A short distance away, we spotted another Andrena doing the same thing.
Life is good.
Andrena bee on meadowfoam. (Photo by Kathy Keatley Garvey)
Andrena bee cradled inside a meadowfoam at the Jepson Prairie Reserve. (Photo by Kathy Keatley Garvey)
At first I thought it was a yellow-faced bumble bee.
Sort of like applying the adage, "When all you have is a hammer, everything looks like a nail." That's because most of the bumble bees I see are the yellow-faced bumble bees (Bombus vosnesenskii).
Our bumble bee guru, native pollinator specialist Robbin Thorp, emeritus professor of entomology, quickly identified it as Bombus melanopygus, commonly known as the “Black Tail” bumble bee (melano = black; pygus = tail end of the abdomen).
Thorp says it's probably a queen that "just started her nest."
"Workers at this time of year would be quite small."
The queen was nectaring on Ceanothus in the Häagen-Dazs Honey Bee Haven, a half-acre bee friendly garden at the Harry H. Laidlaw Research Center at the University of California, Davis.
She was packin' pollen
Initially, Thorp suspected that the pollen load came from the nearby almond trees. "On closer inspection, the pollen loads look more yellow, so they may be from Ceanothus, but they seem a bit darker than what the honey bees foraging on Ceanothus are carrying," he said. "This could be to the difference in nectar added by the different bees to moisten the pollen pellets."
The queen buzzed around the Ceanothus as if she were late for an appointment.
A sip of nectar and she was gone.
Black-Tail Bumble Bee
From the Top
Some species of bumble bees are disappearing at an alarming rate.
And that, in itself, is alarming.
A three-year study published Jan. 3 in the Proceedings of the National Academy of Sciences (PNAS) “uncovered major losses in the relative abundance of several bumble bee species and declines in their geographic range since record-keeping began in the late 1800s,” according to a University of Illinois press release.
The interdisciplinary study, led by Sydney Cameron of the Department of Entomology and Institute for Genomic Biology, University of Illinois, showed that "declining bumble bee populations have lower genetic diversity than bumble bee species with healthy populations and are more likely to be infected with Nosema bombi, an intracellular parasite known to afflict some species of bumble bees in Europe."
“The national analysis found that the relative abundances of four of the eight species analyzed have declined by as much as 96 percent and that their surveyed geographic ranges have shrunk by 23 to 87 percent,” according to the news release. “Some of these contractions have occurred in the last two decades.”
Cameron and his colleagues studied eight of the 50 species of bumble bees found in North America. Of the eight, four are significantly in trouble.
Said Cameron: "They could potentially recover; some of them might. But we only studied eight. This could be the tip of the iceberg.”
Noted bumble bee expert Robbin Thorp, emeritus professor of entomology at UC Davis, today discussed the declining bumble bee population with KTVU Fox 2 health and science editor John Fowler. The segment aired tonight on the 6 o'clock news.
Thorp and Fowler walked around the Häagen-Dazs Honey Bee Haven, a bee friendly garden planted next to the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road. Thorp monitors the garden for bees.
The Cameron study looked at three western bumble bees: Bombus vosnesenskii (yellow-faced bumble bee), B. bifarius, and B. occidentalis.
Of those western bumble bees, only B. occidentalis is in decline “and that one only in the western part of its range,” Thorp told us.
“Although the study treated B. pensylvanicus as the eastern species in decline, the researchers did not consider its very close western relative, B. sonorus, which used to be very common here and the rest of the Central Valley, but has virtually disappeared here since about 2003,” Thorp said.
"Both these species are doing well from the southern USA down into Mexico, however. This is a curious reversal of what one would expect if global warming might be a cause.”
Bumble bees, commercially reared to pollinate greenhouse tomatoes, peppers and strawberries, pollinate about 15 percent of our food crops, valued at $3 billion, Thorp said.
Thorp has been tracking the now critically imperiled Franklin's bumble bee (Bombus franklini) since 1998. "It has the most restricted distribution range of any bumble bee in North America and possibly the world. Its range is about 190 miles north to south and 70 miles east to west in a narrow stretch between southern Oregon and northern California between the coast and Sierra-Cascade range,” he said.
Its known distribution includes Jackson, Douglas and Josephine counties in Oregon and Siskiyou and Trinity counties in California. It lives at elevations ranging from 540 feet in the north to 6800 feet in the south.
The decline, disappearance and possible demise of Franklin’s bumble bee, is closely linked to the widespread decline of native pollinators in North America, Thorp said, and should concern all facets of society. “The loss of a native pollinator could strike a devastating blow to the ecosystem, economy and food supply.”
Yellow-Faced Bumble Bee