Backyard Orchard News
When you visit the Peter J. Shields Oak Grove in the UC Davis Arboretum, you'll see one of the most diverse mature oak collections in the United States. More than 80 kinds of oaks, including scientifically documented trees native to the United States,Central America, Europe and Asia are planted there.
The dominant native oak is the Valley oak, Quercus lobata Née.
What Ian Pearse, a UC Davis researcher in the Department of Entomology, wanted to know was this: "Why do insects interact with some non-native plant species but not others?"
In a study encompassing three summers and 57 species of introduced (non-native) oaks in the grove, he found that many insects that target California’s native oak trees will also feed on non-native oaks planted near them, but with one distinct difference: the insects tend to do more damage to the non-native oaks that are closely related to the natives, than they do to the distant relatives.
“This is a confirmation of the ideas dating back to Darwin,” said Pearse, a doctoral candidate in the Department of Entomology who studies with major professor and noted insect ecologist Rick Karban.
Pearse and co-author Andrew Hipp of the Illinois-based Morton Arboretum and Field Museum of Natural History, Chicago, published their results in a recent edition of the journal, Proceedings of the National Academy of Sciences (PNAS).
“The insects were mostly small moths, fairly inconspicuous,” Pearse said. “They don’t cause a lot of damage. This was more of a theoretical study, of how insects on native oaks also tend to interact with non-native oaks that are similar.”
“Ian's study is important for several reasons,” said Karban. “Our collective intuition about what makes some introduced plants, including crop species, more susceptible to herbivores than others is poorly developed. By using a large number of oak species planted in a common environment, and accounting for the relatedness of the species, Ian can answer that question with a great deal of elegance and power. His finding that relatedness of the various oaks to the native species explains a lot of the picture and provides considerable insight.”
The journal cover features an image of the mural “Oak Family Tree,” from the UC Davis Arboretum oak collection. The mural, created through the UC Davis Art/Science Fusion Program, taught by entomology professor and artist Diane Ullman and artist Donna Billick, depicts the evolutionary relationships of 29 oak species and the animals associated with each species.
“The project was a collaboration with the arboretum,” Ullman said, noting that Emily Griswold, a national leader in oak conservation and the Arboretum’s assistant director of horticulture, “provided the leadership and knowledge base from the arboretum.”
The PNAS article is drawing widespread interest from ecologists, taxonomists and oak enthusiasts. Pearse is the first person to create a phylogeny of the oaks in Shields Oak Grove. Internationally recognized oak expert John Tucker (1916-2008), former UC Davis botany professor and a former director of the Arboretum, helped plant the trees nearly half a century ago.
And now we know more about the insects that interact with those oaks.
Almond pollination season is approaching, and with it, come concerns.
Mussen, a former New Englander who has seen dozens of almond pollination seasons in California (he's been a member of the UC Davis Department of Entomology since 1976), says California now has approximately 710,000 acres of almonds. Each acre requires two hives for pollination.
Since California doesn't have that many bees, beekeepers from around the country truck in their colonies. The going rate per hive over the last several years has ranged from $100 to $150.
Generally, California's almond pollination season starts around Feb. 10, Mussen says, and ends around March 10. That takes into account the early, mid- or late varieties that bloom at different times. However, the pollination period for each individual orchard is around 10 days.
The flight hours of a honey bee during almond pollination season? Approximately nine hours a day over a 10-day bloom period.
And what are flight hours? Mussen defines "flight hours" as "the number of hours above 55 degrees when the wind is less than 15 miles per hour, given a sufficient level of sunlight without rainfall."
"I believe that if the tree varieties overlap well in bloom, the bees usually have moved the pollen around in the morning and early afternoon on good flight days," he writes in his newsletter. "That probably requires only about four hours a day."
Of course, poor weather can interfere significantly with "fertilization and nut set," Mussen says, "but it would not be the fault of the bees."
As a service to beekeepers and growers, a retired beekeeper posts information on the Almond Board of California Web site indicating who's renting colonies and who needs pollination.
Meanwhile, check out the images below of UC Davis bee breeder-geneticist Kim Fondrk in a Dixon, Calif. almond orchard. Fondrk manages the Honey Bee Pollen Hoarding Selection Program at the Harry H. Laidlaw Jr. Honey Bee Research Facility, UC Davis, under the direction of Robert E. Page Jr., Arizona State University. Fondrk and Page moved the bees from Arizona to California several years ago.
The noonhour seminars sponsored every Wednesday through March 10 by the Department of Entomology, University of California, Davis, are drawing widespread interest.
And delightedly so.
Many faculty, students and staff make it a point to attend the 12:10 to 1 p.m. sessions in 122 Briggs Hall, Kleiber Drive, or they listen to the live Webcasts. Most, but not all lectures are being Webcast. (Exceptions: lectures containing unpublished data.)
On Wednesday, Jan. 13, tropical arthropod ecologist Steve Yanoviak with the Department of Biology, University of Arkansas, Little Rock, will speak on "Ecology and Behavior of Tropical Arboreal Ants."
Yanoviak does research in the rain forests of Peru. He recently returned with a fun image of himself (the exuberance expressed in this photo would prompt anyone to want to study ants!) and an image of an arboreal ant, Cephalotes atratus (above). He will be hosted by graduate students Michael Branstetter and Bonnie Blaimer, who study with professor and ant specialist Phil Ward.
Graduate student Ian Pearse of professor Rick Karban's lab is coordinating the winter noonhour seminars. Fellow graduate students James Harwood and Amy Morice, who study with professor James Carey, are devoting their time and talents to Webcasting the seminars. Folks can also access the archived Webcasts dating back to February 2009.
Here's the winter quarter schedule, which includes the live link to the Webcasts.Arboreal ants! Bring 'em on!
Talk about singing the blues.Specifically, the noted "Blue King" (Aster amellus), a member of the sunflower family, Asteraceae.
This is one flower that deserves its own chorus.
At the Harry H. Laidlaw Jr. Honey Bee Research Facility, University of California, Davis, there's a "Blue King" planted close to the back entrance leading to the apiary. It serves a triple purpose: food for the bees; a splash of color for the beekeepers who tend the apiary; and eye candy for photographers and other visitors.
In the late fall and early winter (before the frost), the bees are all over it.
However, soon the "Blue King" will have company. Come spring, the one-half acre Häagen-Dazs Honey Bee Haven and the quarter-acre Campus Buzzway (two bee friendly gardens planted last fall near the facility) will be buzzing with bees.
Circle your calendar: the public opening is June 19.
Working the Flower
James R. Carey is used to dissent.
The entomology professor at the University of California, Davis, fervently believes that the Mediterranean fruit fly and light brown apple moth, two exotic and invasive pests, have long been established in California and cannot be eradicated.
Trying to eradicate them, he says, is like "throwing money down a rathole."
Check out the current (Jan. 8th) edition of Science Magazine and read the three-page NewsFocus piece headlined "From Medfly to Moth: Raising a Buzz of Dissent."
This is sure to garner a plethora of comments, concern and criticism. This is about as high-profile as it gets in the scientific community. And this is not the message that the California Department of Food and Agriculture (CDFA) is trying to get across. (See CDFA's Web site on the light brown apple moth).
Carey, a Fellow of the American Association for the Advancement of Science, just completed a term as the chair of the UC Systemwide Academic Senate University Committee on Research Policy. He also directs a federally funded program on lifespan and aging; the program just received a $3.4 million grant renewal from the National Institute on Aging.
"James Carey is at it again," began writer Ingfei Chen of Santa Cruz. "In the early 1990s, as a scientific adviser in California's unpopular pesticide-spraying war against the Mediterranean fruit fly, the entomologist vocally charged that the state's program was fundamentally flawed. Bucking conventional wisdom, Carey claimed that the Medfly was already established, defying the eradication attempt."
Fast forward to February 2007 and the discovery in California (Bay Area) of a new invasive pest, the light brown apple moth, a native of Australia.
Aerial spraying of a pheromone resulted in a "red-hot-public ruckus, forcing the state to shift to a plan to release zillions of sterile moths...And once again, Carey has surfaced as a relentless voice of dissent," Chen wrote.
Carey insists it can't be eradicated, that it's here to stay and we ought to focus on pest management, not eradication.
What's next? Michael Parrella, professor and chair of the Department of Entomology wants to organize a spring conference "to reexamine the invasive species-policy paradigm from to bottom," Chen wrote.
"The goal," she wrote, "is an open dialogue with major stakeholders," including the U.S. Department of Agriculture and CDFA.
Carey told us today that Parrella plans to meet with him and a group of other entomologists next week to discuss the proposed workshop.
"It would be nice to think we could sit down and discuss things," Parrella told Chen in the Science Magazine article. "It's not us versus them."
Light Brown Apple Moth