The “Faithfulness” Of Honey Bees as Pollinators Of Red Clover

Sarah Maxfield-TaylorOregon State University

Summer REU Program For Pollination Biology

Are honey bees (Apis mellifera L.) “faithful” pollinators of red clover?

• Red clover crop production

• Pollen sampling

• Pollen identification

• Future research topics

Presentation Outline

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 worththe cost?

MethodsPollen 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

7-13-09 7-21-09 7-28-09 8-03-09 8-11-09

HAMILTON

KENNEL

7-13-09 7-21-09 7-28-09 8-03-09 8-11-09

7-13-09 7-21-09 7-28-09 8-03-09 8-11-09

7-13-09 7-21-09 7-28-09 8-03-09 8-11-09

SIMPSON

Early Bloom Bloom Peak Late Bloom Bloom End

Honey bee pollen loads collected from

all three sites

Bull ThistleCirsium vulgare

Canada ThistleCirsium arvense

False DandelionHypochoeris radicata

Prickly LettuceLactuca sernola

Common MallowMalva neglecta

Stinking MayweedAnthemis cotula

Queen Anne’s LaceDaucus carota

Morning GloryConvulvulus arvensis

TeaselDipsacus fullonum

Field MustardBrassica campestris

Wind FlowerEpilobium ciliatum

Sharp point fluvellinKickxia elatine

Saint Johns WartHypericum perforatum

Sweat PeaLathyrus latifolia

Tansy RagwortSenecio jacobaea

Red CloverTrifolium pratense

Arrowleaf CloverTrifolium vesiulosum savi

False DandelionHypochoeris radicata

A single pollen load collected 7-13-09 from the Hamilton site

Red CloverTrifolium pratense

?

A second pollen load collected 7-13-09 from the Hamilton site

False DandelionHypochoeris radicata

?Unknown

Asteraceae

Saint Johns Wart Hypericum perforatum

Red Clover Trifolium pratense

Arrowleaf Clover Trifolium vesiulosum

A third pollen load collected 7-21-09 from the Hamilton site

Dandelion

?

Red CloverTrifolium pratense

False DandelionHypochoeris radicata

A single pollen load collected 7-21-09 from the Kennel site

Red CloverTrifolium 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