Posts Tagged: Robbin Thorp
Let's have a show of hands.
How many of you have seen Franklin's bumble bee in the wild?
Never HEARD of it, you say?
Well, you probably will never SEE it, either. Bumble bee experts think it may be extinct.
Franklin's bumble bee is native to southern Oregon and northern California, but in recent years, it's been a "no show."
"Franklin's bumble bee has the most restricted distribution range of any bumble bee in North America, and possibly the world," said UC Davis researcher Robbin Thorp, a noted authority on bumble bees. 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 the Sierra-Cascade ranges.
Its known distribution: 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.
Thorp launched his scientific surveys for Franklin's bumble bee in 1998. He documented about 100 of them that year. They were, he said, fairly common.
Since 2004, however, he's seen the unique bumble bee only once. And that was a solitary worker in August 2006 at Mt. Ashland, Ore.
The black-faced bumble bee (Bombus franklini) is distinguished by a black inverted U-shape on its yellow thorax. See Thorp's photo below. Note also the yellow markings atop its head.
Franklin's bumble bee frequents (or shall we say, "used to" frequent) California poppies, lupines, vetch, wild roses, blackberries, clover, sweet peas, horsemint and mountain penny royal during its flight season, from mid-May through September. It collects (or shall we say "used to" collect) pollen primarily from lupines and poppes and gathers nectar mainly from mints.
Thorp just returned from the region in mid-May and found nothing. He journeys to the region three to five times a year, spending several days looking for the bumble bee on each trip.
It's not there.
Thorp is concerned, as we all should be, that humankind is disturbing, destroying and altering the habitat where the native pollinators exist.
He'll be speaking on the plight of the bumble bee from 12:10 to 1 p.m., Wednesday, May 27 at 122 Briggs Hall, UC Davis. His talk will be Webcast. You can view it by signing in here at that time. Later, it will be archived on this page.
Bumble bees, Thorp said, are important to our ecosystem. Wildlife, including birds, elk, deer and bears, depend on pollination of fruits, nuts and berries for their survival.
Other species of bumble bees are commercially reared to pollinate greenhouse tomatoes, peppers and strawberries. They pollinate about 15 percent of our food crops, valued at $3 billion, Thorp estimated.
Goodbye, Franklin's Bumble Bee? Hello, distinction?
It wasn't the Battle of the Sexes.
It was the Battle of the Males.
I spotted two male carpenter bees buzzing loudly over the salvia (sage) in our back yard Saturday morning. Each was lying in wait for a female, but instead found a competitor.
Now male carpenter bees are quite territorial and these two were no exception. The would-be suitors chased one another all over the yard, from saliva to salvia. One would buzz into a blossom for a quick nectar fix and the other would aggressively chase it away.
One stopped long enough, however, for me to capture his photo.
Ol' Blue Eyes.
UC Davis entomologist-pollinator specialist Robbin Thorp, professor emeritus, identified this male as a Xylocopa tabaniformis orpifex Smith
It's the most common carpenter bee in the Davis area, Thorp said. "It loves to nest in redwood structures: fences, arbors, picnic tables, etc. It is the smallest of the three carpenter bees in California. The males are quite variable in hair color on the thorax: from virtually all dark, to some yellow in front of the wing bases, to virtually all yellow on top."
Another carpenter bee increasingly found in the Davis area is the valley carpenter bee. The sighting of the male, a green-eyed fuzzy yellow "teddy bear," prompts lots of calls to the UC Davis Department of Entomology. "What is it?" they ask.
We point them to our Web page for the scoop on the three types of carpenter bees found in California.
As spring unfolds, expect to see more of them.
Ol' Blue Eyes
Ol' Green Eyes
When you think of a teddy bear, you think of a huggable stuffed animal.
Not so entomologists. When they think of a teddy bear, they think of the male Valley carpenter bee.
It's a green-eyed, fluffy golden insect that's nicknamed "teddy bear." You can hug it, too. Unlike the females, male carpenter bees don't sting.
When a Davis resident recently cut down a plum tree, hordes of buzzing insects tumbled out. Seeking identification, the resident carted a chunk of the wood and the golden insects into the Bohart Museum of Entomology.
What were they?
“Male carpenter bees, Xylocopa varipuncta, also known as Valley carpenter bees,” said entomologist Lynn Kimsey, director of the Bohart Museum of Entomology and professor and chair of the UC Davis Department of Entomology.
“Some of us refer to these males as ‘teddy bear’ bees, because of their yellowish-brownish color and fuzzy burly bodies,” said UC Davis emeritus entomology professor Robbin Thorp, who studies pollinators. “The females are all black with violaceous (violet) reflections on their dark wings.”
Carpenter bees, so named for their ability to tunnel through wood to make their nests, carve with their mandibles (jaws) but do not ingest the wood. Only the females excavate the tunnels, which average six to 10 inches in depth.
Thorp says he tries to convince people to learn to live with these bees as “they are important pollinators in our environment and have potential as pollinators of some crops.”
“Carpenter bees are beneficial in that they pollinate flowers in native plant communities and gardens,” he said. “That far outweighs any damage to wood structures.”
California is home to three carpenter bee species. I've seen X. tabaniformis orpifex buzzing around my backyard but never The Golden One.
What a gorgeous insect!
Those dratted mites.
UC Davis entomologist Robbin Thorp, emeritus professor and a native bee pollinator specialist, sent us a BBC report linking a varroa mite infestation to a devastating honey production loss in the UK. It's the worst honey crisis ever to hit the UK.
In short: beekeepers are concerned that by Christmas, there may be no more domestically produced honey left on the supermarket shelves.
The mite infestation has already killed off an estimated quarter of the UK's honey bees, according to BBC correspondent Jeremy Cooke, who said about "one in three colonies has been wiped out."
The varroa mite, or the Varroa destructor, is a nasty pest. Now found in most countries (Australia is an exception), it's an external parasite initially discovered on the Asian honey bee, Apis cerana. Over the last few decades, however, it has spread to the Western honey bee (also known as the European honey bee), Apis mellifera.
The varroa mite entered the UK in 1992, reports show. It has since spread throughout England, Wales, Scotland and Northern Ireland.
The blood-sucking parasite feeds on both adults and the brood (immature larvae). It weakens the bees, opening them up to all sorts of diseases. And eventually, if not controlled, it will destroy the colonies.
The bad news is that the varroa mite cannot be completely eradicated, but with proper control methods, the mite population can be kept at a low level.
When California State Secretary of Agriculture A. G. Kawamura visited the Harry H. Laidlaw Jr. Honey Bee Research Facility at UC Davis last month, bee breeder-geneticist Susan Cobey showed him dead mites on a hive floor. (See story on UC Davis Department of Entomology site.)
Kawamura is no stranger to bees or bee pests. As a youth, he reared bees--until the infectious bee disease, American foulbrood, upset his plans.
To control the mite, beekeepers usually use a combination of management methods. They use biotechnical methods and chemical controls. Unfortunately, in some areas, the varroa mite is developing resistance to miticides--another worry for beekeepers.
Said Cobey: "You need to reduce mite levels in colonies by late summer--August/September--to have healthy bees in spring."
Cooperative Extension apiculturist Eric Mussen of UC Davis says that in California, the Department of Pesticide Regulation "is close to approving another chemical treatment" to help control the mite problem.
It may be ready by next spring.
The mites will be waiting.
Mite on Drone
Mites on Hive Floor
They danced in it, rolled in it, and bathed in it.
The honey bees just couldn’t get enough of the rock purslane (Calandrinia grandiflora).
Last week when we visited
Nearby, two other bees, sisters in honeyhood, shared the same flower as another honey bee tumbled happily out of her flower and made a beeline for the next one.
Ernesto Sandoval, curator of the College of Biological Sciences Greenhouses at UC Davis and Robbin Thorp, emeritus professor of entomology at UC Davis, say that bees love Calandrinia grandiflora. The plant, native to Chile, blooms here in late summer and early fall.
"It has has bright red-orange pollen that honey bees love," Thorp said.
They do, indeed.
What do you mean, I'm too big?
Flight of the honey bee