Posts Tagged: digger bee
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)
Diggin' the digger bee...
We spotted this female digger bee, Anthophora urbana, zooming in on some zinnias at UC Davis. She buzzed loudly, virtually owning the zinnia patch. Smaller sweat bees scattered.
The bee, identified by native pollinator specialist Robbin Thorp, emeritus professor of entomology, is a solitary, ground nesting bee. "She has been around for a while judging by the worn (hairless) patch in the middle of the thorax," Thorp points out. "She has a dense brush of white hairs on her hind legs (scopa) for pollen transport."
Anthophoridae, described by Christopher O'Toole and Anthony Raw in their book, Bees of the World, is a "very large family...found in all parts of the world. Many are robust and resemble bumble bees."
"Most species nest in the ground while a few excavate in dead wood," they write.
The genus, Anthophora, includes more than 450 species worldwide. It's one of the largest in the Apidae family, which includes honey bees, carpenter bees, bumble bees, cuckoo bees and the like.
Anthophora urbana differs sharply from our honey bee, Apis mellifera.
The honey bee is social, living in a hive with some 60,000 other bees and sharing the workload. The digger bee is solitary.
The honey bee gathers nectar and pollen (and also propolis, from plant resin) and makes honey. The digger bee forages for nectar and pollen but does not make honey.
Occasionally, as floral visitors, they bump into each other. The social and the solitary...
Female digger bee, Anthophora urbana, on zinnia. (Photo by Kathy Keatley Garvey),
Female digger bee, Anthophora urbana, peers over the petals of a zinnia. (Photo by Kathy Keatley Garvey)
Caught in flight, a female digger bee, Anthophora urbana, heads for a zinnia. (Photo by Kathy Keatley Garvey)
If that word is not in your everyday vocabulary, just think of a symbiotic relationship where one organism transports another organism of a different species for the benefit of both.
And there you have it--at least part of it--of what evolutionary ecologist Leslie Saul-Gershenz of the University of California, Davis, is doing.
Saul-Gershenz researches 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.
She and Neal Williams (her major professor) of UC Davis and Jocelyn Millar of UC Riverside just received a grant to study digger bee ecology and conservation. They're working with SaveNature.Org, which Saul-Gershenz co-founded.
The relationship between the bee and the blister beetle is part of it.
What's this symbiotic relationship about? The larvae of the parasitic blister beetle produce a chemical cue or a pheromone similar to that of a female solitary bee to lure males to the larval aggregation. The larvae attach to the male bee and then transfer to the female during mating. The end result: the larvae wind up in the nest of a female bee, where they eat the nest provisions and likely the host egg, Saul-Gershenz says.
Like to read more about this exciting research? Saul-Gershenz and Millar published their blister beetle/digger bee work, "Phoretic Nest Parasites Use Sexual Deception to Obtain Transport to their Host's Nest," in the Proceedings of the National Academy of Sciences (PNAS, 2006).
That led Pulitzer Prize-winning author Natalie Angier to feature their work in "The Art of Deception," published in the August 2009 edition of the National Geographic magazine. Most recently, U. S. Department of Agriculture (USDA) Forest Service entomologist Michael Ulyshen, writing for the Journal of Natural History, mentioned their work in "Bugback Riding: Transportation for the Masses" (September 2011).
Saul-Gershenz said she became interested in the subject while she was a graduate student at San Francisco State University. She wrote "Beetle Larvae Cooperate to Mimic Bees" in the journal Nature (2000).
Of her newest grant, she says: “Our preliminary data show that the blister beetle exploits four other native California bees including important pollinators in the genus Habropoda and Anthophora." Historically, M. franciscanus was known to be a nest parasite of Anthophora edwardsii distributed throughout California.
You may know Saul-Gershenz as a past president of the Pacific Coast Entomological Society. In 1991, she became the first female president in its 91-year history.
Larvae of a blister beetle, Meloe franciscanus, on a digger bee, Habropoda pallida. (Photo by Leslie Saul-Gershenz, used with permission)
Digger bee, Habropoda pallida, a solitary ground-nesting bee, on Borrego milkvetch. (Photo by Leslie Saul-Gershenz, used with permission)