The “Faithfulness” Of Honey
Bees as Pollinators Of Red
Clover
Sarah Maxfield-Taylor
Oregon State University
Summer REU Program For Pollination Biology
Presentation Outline
Are honey bees (Apis mellifera L.) “faithful” pollinators
of red clover?
• Red clover crop production
• Pollen sampling
• Pollen identification
• Future research topics
Oregon Clover Seed Production
32,000 Acres Of Clover (2,000 Acres of red clover)
• Forage crop grown for livestock
• Rotation crop
Pollination as a limiting factor
Bumble bees are not a commercial option in Oregon.
What is the cost of using honey bees to pollinate red
clover?.....
• $55/hive rental fee
• Minimum of 1 hive/2 acres (2/acre avg.)
• Mixed pollination results
Are the services they provide worth
the cost?
Methods
Pollen Collection
• Red clover field sites in the Willamette Valley
• Samples were taken with a Sundance pollen trap
Pollen analysis
• Samples separated out by color
• Scanning Electron Microscope analysis
• Reference plant collection
Results
• Change in pollen color
throughout season
• Plant families identified
HAMILTON
Honey bee pollen loads collected from all three sites
7-13-09
7-21-09
7-28-09
8-03-09
8-11-09
8-03-09
8-11-09
KENNEL
7-13-09
7-21-09
7-28-09
SIMPSON
7-13-09
7-13-09
Early Bloom
7-21-09
7-21-09
7-28-09
Bloom Peak
7-28-09
8-03-09
8-03-09
Late Bloom
8-11-09
8-11-09
Bloom End
Bull Thistle
Cirsium vulgare
Canada Thistle
Cirsium arvense
False Dandelion
Hypochoeris radicata
Prickly Lettuce
Lactuca sernola
Common Mallow
Malva neglecta
Stinking Mayweed
Anthemis cotula
Queen Anne’s Lace
Daucus carota
Morning Glory
Convulvulus arvensis
Teasel
Dipsacus fullonum
Field Mustard
Brassica campestris
Wind Flower
Epilobium ciliatum
Sharp point fluvellin
Kickxia elatine
Saint Johns Wart
Hypericum perforatum
Sweat Pea
Lathyrus latifolia
Tansy Ragwort
Senecio jacobaea
Red Clover
Trifolium pratense
Arrowleaf Clover
Trifolium vesiulosum savi
A single pollen load collected 7-13-09
from the Hamilton site
Red Clover
Trifolium pratense
?
False Dandelion
Hypochoeris radicata
A second pollen load collected 7-13-09
from the Hamilton site
?
Unknown
Asteraceae
Red Clover
Trifolium pratense
Arrowleaf Clover
Trifolium vesiulosum
Saint Johns Wart
Hypericum perforatum
False Dandelion
Hypochoeris radicata
A third pollen load collected 7-21-09
from the Hamilton site
Dandelion
?
False Dandelion
Hypochoeris radicata
Red Clover
Trifolium pratense
A single pollen load collected 7-21-09
from the Kennel site
Red Clover
Trifolium pratense
Conclusion
• Foraging behavior
changes throughout the
season
• Honey bees are visiting
red clover
• Honey bees are visiting
non-crop species
• Additional pollen
identification needed
Future Reseach
• Continuation of pollen analysis
• Acetolyosis
• Reference collection
Acknowledgements
• My fellow REU student
researchers
• Sujaya Rao, Andy Moldenke,
Sandy DeBano, Bill Steven,
Jeff Miller, and all those
involved with O.S.U.’s
Pollination Biology REU
• Terresa Sawyer at
O.S.U’s S.E.M. laboratory
• Lynn Royce-Mite Bee Farms
• Chiho Kimoto, Kimberly
Skyrm, Julie Kirby, and
Toni Taylor
• The NSF
• HHMI
Thank you all