Posts Tagged: Robbin Thorp
What's that? A honey bee and a male yellowjacket on the same blossom?
Honey bees and yellowjackets belong to the same order, Hymenoptera, but different families. The honey bee (Apis mellifera) is in the Apidae family, while the yellowjacket, Vespula pensylvanica, belongs to the family, Vespidae.
When beekeepers open the hives at the adjacent Laidlaw facility, trouble can start between the honey bees and the yellowjackets. It's no secret that female yellowjackets establish their nests near apiaries to prey upon honey bees and their brood. They need the protein for their offspring.
But here they were--the honey bee and the yellowjacket--together.
The first occupant: the honey bee. She began foraging on a rose blossom when suddenly a male western yellowjacket approached her. Seemingly unaware of his presence, she kept foraging. He poked her with his antennae. She ignored him. He crawled up next to her and took a close look at her. She kept foraging.
A few seconds later, he left.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, later commented: "I can't help but wonder why the male yellowjacket was visiting a rose flower--no nectar there, so no reward for him."
"Maybe he was just checking out the other occupant 'while searching for love in all the wrong places.' "
Indeed, the male yellowjacket may have been looking for a suitable mate.
This one? Definitely not suitable!
Male yellowjacket heads toward a honey bee. (Photo by Kathy Keatley Garvey)
Male yellowjacket checks out the honey bee. (Photo by Kathy Keatley Garvey)
Honey bee continues to forage, while the male yellowjacket crawls away. (Photo by Kathy Keatley Garvey)
The latest edition of Fremontia, a publication of the California Native Plant Society (CNPS), is devoted to the state's declining prairies and grasslands.
"Humans are largely responsible" for this decline, writes editor Bob Hass. "We exploit natural resources for basic human needs and for consumable. But too few of us pay attention to the effect our actions have on the environment. Fewer still make the connection between an eroding environment (polluted water, air, soil from toxic chemicals) and cumulative impacts to human health (cancer, birth and immune system defects) or to plants and animals (disease, acid rain, increased toxins accumulating in the food chain)."
So true. And as Hass says "Nature cannot protect itself from what we humans do to the environment, but we can."
We were especially interested in the article, "Native Bees and Flowers in California Prairies and Grasslands" by native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis and a 35-year member of CNPS.
He quoted John Muir in his book, The Mountains of California: "When California was wild, it was one sweet bee-garden throughout its entire length...the Great Central Plain of California, during the months of March, April, and May, was one smooth, continuous bed of honey-bloom, so marvelously rich that in waking from one end of it to the other, a distance of more than 400 miles, your foot would press about a hundred flowers at every step."
Not so today! No wonder the bees are suffering from malnutrition (not to mention other issues).
Thorp calls attention to some of the flowers found today in the Central Valley grasslands. "Our state flower, the California poppy (Eschscholzia californica) produces no nectar, but only pollen as a reward to bees...Generalist bumble bees (Bombus spp.) and sweat bees (Halictus spp.) are the main visitors, along with small pollen feeding beetles."
Thorp illustrated his article with a beautiful photo by Davis plant/insect enthusiast and photographer Gary Zamzow of the yellow-faced bumble bee (Bombus vosnesenskii) foraging for pollen on a California poppy. Thorp also included several other photos.
No doubt you've seen honey bees foraging on California poppies, but as Thorp says, poppies provide no nectar, only pollen.
Worker bumble bee, Bombus vosnesenskii, foraging on a California poppy. (Photo by Gary Zamzow)
This photo, of a female sweat bee, Halictus ligatus, on a gumplant also appears in the Fremontia article. (Photo by Kathy Keatley Garvey)
Male cuckoo bee (Triepeolus sp.) foraging on a gumplant. This is another photo in the Robbin Thorp. piece. Cuckoo bees do not gather pollen. (Photo by Kathy Keatley Garvey)
It's not often you see a monarch butterfly and a digger bee in the same photo.
Such was the case on a recent visit to a lantana patch at a west Vacaville home.
The monarch butterfly touched down on a blossom and was beginning to nectar when along comes a digger bee, a male Anthophora urbana (as identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology at the Universit of California, Davis.)
"Maybe it was planing on dive bombing the big intruder from his territory," Thorp said. "However, these males are not known to be especially territorial. Maybe he's just checking out the competition for nectar."
This is the solitary, ground-nesting bee that Leslie Saul-Gershenz, graduate student in the Neal Williams lab at UC Davis, is researching. She's published research on a species of digger bee, Habropoda pallida, a solitary ground-nesting bee, and its nest parasite, a blister beetle, Meloe franciscanus, found in the Mojave Desert ecosystem.
Now she's also including Anthophora.
“Our preliminary data show that the blister beetle exploits four other native California bees including important pollinators in the genus Habropoda and Anthophora," she recently told us.
Historically, the blister beetle, Meloe franciscanus, was known to be a nest parasite of Anthophora edwardsii, distributed throughout California.
See her amazing photo of the parasitic larvae of the blister beetle on the digger bee, Habropoda pallida, on the UC Davis Entomology website.
Monarch butterfly nectaring lantana, while a digger bee, Anthophora urbana, heads toward it. (Photo by Kathy Keatley Garvey)
Honey bees on blanket flowers (Gaillardia).
Honey bees on Mexican sunflowers (Tithonia).
The Girls of Autumn....not unlike The Boys of Summer...
Extension apiculturist Eric Mussen of the UC Davis Department of Entomology, emphasizes that backyard gardeners should plant bee friendly flowers for all the seasons.
'Limited plantings of backyard, or even acres, of flowers will greatly improve the possibility of enhancing the native bee population in the area," Mussen says. "However, each honey bee colony requires an acre equivalent of forage on a daily basis, all during its active season. This seems to be pretty hard to accomplish, but honey bees will fly up to four miles from the hive in any compass direction to get food. That is an area of 50 square miles in which to find that acre equivalent."
G. H. Vansell, author of the University of California's treasured 1941 bulletin, "Nectar and Pollen Plants of California," writes that "six of the most important sources of nectar in California are the sages, alfalfa, orange, wild buckwheats, star thistle and Christmas berry; of these, the sages, wild buckwheats and Christmas berry are native." (Read this book online in openlibrary.org.)
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, has singled out some of the best native plants for bees. The information, gleaned his own experience and from Vansell's list, appears on the website of the Harry H. Laidlaw Jr. Honey Bee Research Facility, UC Davis.
And if you want to look up individual plants, Thorp urges you to access Calflora (UC Berkeley).
Good advice and a good way to help the bees!
Honey bee on a blanket flower, Gaillardia. (Photo by Kathy Keatley Garvey)
Honey bee on a Mexican sunflower (Tithonia). (Photo by Kathy Keatley Garvey)
Many of us in California have never seen the Western bumble bee (Bombus occidentalis)
Many of us never will.
Native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis, worries about the declining population and fears it may go the way of Franklin's bumble bee, which he hasn't seen since 2006.
That's why he and his colleagues were so excited to find a male Bombus occidentalis on Mt. Shasta, above 5,000 feet, on Aug. 15. It was foraging on buckwheat (Eriogonum sp.).
Thorp was there with several local U.S. Forest Service employees: wildlife biologist Debbie Derby, who actually netted the bee; and biological technicians Susan Thomas, Kendra Bainbridge and Lauran Yerkes.
"Just as we were celebrating the find, we were joined by two other USFS personnel: Carolyn Napper, district ranger, and Johnny Dame, Panther Campground host," Thorp recalled. "So there were lots of witnesses to the rare find."
A rare find, indeed.
The Western bumble bee, a close relative of Franklin's bumble bee (Bombus franklini), "disappeared from the western part of its range at the same time as Franklin's bumble bee declined," said Thorp, who keeps an eye out for both species on his trips to southern Oregon and northern California.
The habitat of the Franklin's bumble bee, which many fear is extinct, is a 13,300-square-mile area of Siskiyou and Trinity counties in California, and Jackson, Douglas and Josephine counties in Oregon.
"The Western bumble bee occurred throughout the range of Franklin’s, but apparently declined from central California to southern British Columbia west of the Sierra Cascade Range at the same time as the decline of Franklin's bumble bee, " Thorp said.
However, the Western bumble bee "seems to have persisted through most of the rest of its range from Alaska through areas east of the Sierra-Cascade to the Rocky Mountains and south to Arizona and New Mexico," Thorp pointed out. "We have no good idea what the population trends have been within this large area, since no one has been closely monitoring its populations there."
We're glad to see the increased interest in bumble bees. And especially glad to see that this week the Xerces Society for Invertebrate Conservation announced the publication of Bumble Bees of the Western United States, co-authored by Jonathan Koch, James Strange and Paul Williams. You can order it online.
Bombus occidentalis and Bombus franklini are among the Bombus species represented.
Close-up of a male Western bumble bee (Bombus occidentalis) found Aug. 15 at Mt. Shasta. (Photo by Kathy Keatley Garvey)
Another view of the male Western bumble bee found on Mt. Shasta. (Photo by Kathy Keatley Garvey)
Documenting the rare find. (Photo by Kathy Keatley Garvey)
Native pollinator specialist Robbin Thorp is a retired UC Davis professor, but continues his full-time research. (Photo by Kathy Keatley Garvey)