Bacteria Help Honeybee Larvae Thrive
By Kim Kaplan, ARS Information Staff, "Agricultural Research" Magazine
Honey bees are under constant pressure from a whole host of stresses-diseases, poor nutrition,
sublethal effects of pesticides, and many others. While researchers have been aware for a number of
years of a community of bacteria in adult bees that may aid with some of these stresses, Agricultural
Research Service researchers have identified the first bacteria that offer a benefit to bee larvae.
Molecular biologist Vanessa Corby-Harris and microbial ecologist Kirk E. Anderson at the ARS Carl
Hayden Bee Research Center in Tucson, Arizona, have named a new species of bacteria
Parasaccharibacter apium. An Acetobacteraceae so far found only in honey bees and their hives, it
appears to give honey bee larvae a significantly better chance of surviving to become pupae.
Honey bees have four major life stages: egg, larva, pupa, and adult.
Work on P. apium was initiated by an earlier post-doctoral researcher, Lana Vojvodic, who first
discovered that these bacteria were abundant in larvae and also thrived in royal jelly. Royal jelly is a
protein-rich substance produced by adult bees in their hypopharyngeal glands, which resemble bunches of grapes on each side of the head. Nurse bees secrete and feed the jelly, which may contain P. apium, to
young bee larvae. This jelly is the only food bee larvae eat during their first couple days. Then they are
fed increasingly more honey, which has also been found to contain P. apium in most bee hives.
In laboratory experiments designed by Corby-Harris, bee larvae were fed either P. apium-spiked jelly or
sterile control jelly. The group fed P. apium had a 20-percent better survival rate in the first trial and a
40-percent better survival rate in the second trial.
"We haven't yet identified what P. apium does that confers this survival advantage to the larvae. It could
involve the production of organic acids and lowering pH, which might have an antiseptic effect, or its
presence might induce an immune response that could later work against larval pathogens," Corby-
While P. apium found in honey bee hives is a distinct and new species from any previously identified, it
has very close, naturally occurring relatives found in the nectar of many flowers, including cactus
flowers, daisies, thistles, and apple blossoms.
Acetobacteraceae bacteria from flowers have not been tested yet to see if any of them might provide bee
larvae with the same survival benefit, nor has there been a wider survey to determine the occurrence of
P. apium-like species in economically important crops visited by bees.
"We have sequenced the genome of P. apium and begun to dissect the functional properties that
distinguish flower-living Acetobacteraceae from those that have coevolved with the honey bee hive.
Pinpointing these ecological differences will be key to understanding the function of P. apium in honey
bee hives," says Anderson.
With minimal sampling effort, P. apium was found in nearly every one of the healthy managed bee
colonies examined by the researchers. A future study will explore the abundance of P. apium in weak or
struggling managed bee colonies.
While the mechanism by which the bacteria benefit the larvae remains to be studied, the importance is
clear enough that Corby-Harris and Anderson are already field testing its use as a management tool.
"Along with P. apium, we are testing a number of bacteria that may benefit the pollination and honeyproduction
industry," says Corby-Harris.
"More broadly, our research suggests that a community of bacteria that includes P. apium confers a
generalized hygienic quality to the hive environment," says Anderson. "So we advise against
unnecessary use of antibiotics by beekeepers, as it likely disrupts the variety and balance of microbial
functions occurring throughout the hive, including the antiseptic properties of honey, pollen storage,
larval health, and pathogen protection."
Going Native In The Garden Is Earth-Friendly
By Carol Savonen, Oregon State University
Landscaping with native plants not only protects our natural heritage if used appropriately, these
plants reduce fertilizer, pesticide and irrigation needs, thereby reducing costs to you and the
More public places are going "native." Schools and parks are incorporating regionally native plants
and employing landscaping practices that conserve water and prevent pollution.
Many plants native to the Pacific Northwest make beautiful and resilient additions to the home
landscape, as well.
Native plants are adapted to regional soils and to regional patterns of wet winters and dry summers,
so they require less pampering than plants imported from other parts of the world. In addition, native
plants, especially shrubs with berries, provide the best food for native birds and wildlife.
But this doesn't mean that you can just plant them and walk away, says Linda McMahan, native plant
expert and horticulturist with the Oregon State University Extension Service.
"Many gardeners make the mistake of thinking that native plants can fend for themselves in the
garden," said McMahan. "Establishing native plants requires care. Knowing the plant's native habitat
can help find the right garden conditions."
Each type of native plant has its own requirements for temperature, moisture, light, soil and terrain.
Pay attention to the microenvironments in your home landscape and purchase or propagate and plant
natives accordingly. A visit to the library, bookstore and native plant websites can provide a wealth of
information on particular requirements of native plants.
To landscape a dry, sunny area on the west side of the Cascades, consider the Willamette Valley form
of ponderosa pine, bitter cherry, Oregon white oak, California lilac, hairy manzanita, western mock
orange, western serviceberry, red-flowering currant, tall Oregon grape, coastal strawberry, Douglas
aster, blue-eyed grass, goldenrod, Oregon iris, pearly everlasting, Cascade penstemon, yarrow and
For dry sunny areas east of the Cascades, McMahan recommends western juniper, yellow currant,
quaking aspen, paper birch, western birch, Oregon grape, sagebrush, wild rose, penstemons and western
West side hedgerows can be beautified with natives including Douglas hawthorn, wild rose or
western serviceberry—all of which also provide food for wildlife. For early blossoms and decorative
bark, consider Pacific ninebark, in wetter areas.
In shadier spots on the west side, consider natives such as western red cedar, blue elderberry, Indian
plum or osoberry, evergreen huckleberry and wild strawberry. Wild ginger is a handsome and adaptable
ground cover that stays green all year. Wild ginger's brownish flowers, pollinated by beetles or flies,
make fascinating surprises in the spring. They sometimes bloom again in the summer or fall. If you have
a moist area, vine maple, creek dogwood, white inside-out flower, small flowered alumroot, sword fern
and western bleeding heart do well.
Many native plants are available from nurseries. Demand is high enough to keep specialty growers in
business propagating native plants. Never dig up native plants from the wild, unless the area is under
certain threat of destruction, such as new construction sites or logged areas and you have written
permission to collect. And remember, it is illegal to collect plants from state and national parks and in
other designated natural areas without a permit.
McMahan has loaded up the website of the Yamhill County office of the OSU Extension Service:
(http://extension.oregonstate.edu/yamhill/eco-gardening/native-plant-gardening) with a wealth of
information and great links about gardening with native plants, including native plant lists for woodland
and sunny border gardens and a downloadable source list where to get the plants in western Oregon.
McMahan has just published a new OSU Extension Service guide "Gardening with Oregon Native
Plants West of the Cascades," (EC 1577). It is available on CD for $10 plus shipping and handling.
place an order, call 1-800-561-6719.