Exploring relationships between pollinators and canola

Rachel Olsson, Dave CrowderWashington State University

image source: Cheryl Dudley

Bees prefer

• Larger petals• More flowers• More nectar• More sugar

Thomson et al., 2012, Harder, 1986, Nguyen & Nieh, 2012, Galen & Newport, 1987

We went to the field!

• Flower sampling• Nectar abundance*• Nectar sugar

concentration*• Pathogen sampling

Petal Size

image source: CropPro

Rhizoctonia AG8-C1

Time to First Flower

18.14 days 18.32 days

t97 = -1.03, p= 0.31

Petal Area (mm2)

t97= -2.56, p= 0.01

26.19 mm2 27.31 mm2

Flowers Open on 5th Day

15.29

21.67

t97= -5.33, p< 0.001

Later blooming plants had more flowers

Upcoming projects (2018-2019)

• Landscape• Farm management• Canola floral traits• Bee nutrition

Landscape

Fig 1. In 2013 and 2014 we sampled canola fields distributed across the Palouse (2013 locations shown in panel A). The landscape around these fields ranged from (B) little to (C) considerable amounts of bee-friendly habitat

Fig. 2. Our data suggest that (A) the acreage of semi-natural habitat around canola promotes yield (P = 0.01) and (B) higher sugar in nectar increases bee abundance in canola (P = 0.03).

Our previous data suggest that more natural land surrounding a canola field promotes canola seed yield and higher nectar sugar concentration. This may lead to higher bee abundance in these fields, resulting in that higher yield.

Farm management

• Canola variety• Glyphosate use• Neonicotinoid use• Crop rotation• Soil traits

• pH• Organic matter• Nutrient levels• Microbial biomass

Canola floral traits

• On Farm• 20 plants per farm• Petal size• Floral abundance• Nectar sugar concentration• Pollen protein

• Greenhouse• Herbivores• Pathogen• Water stress

Bee nutrition

• Lab reared colonies• Feed varying sugar and protein diets that reflect canola

variation• Measure colony growth, pollination performance

• Lab and field cages

• Behavior/ attraction• Varying nutrients, pathogen, herbivore

Thank you!

• Crowder Lab• Dr. Robert Schaeffer• Matthew Brousil• Karen Sowers• Rachel Bomberger• Dr. Elinor Lichtenberg• Dr. Tim Paulitz• Jason Kelton• Dr. Jamie Strange• Alli Cramer• All of our grower collaborators @RLOlsson

References• Galen, A. C., & Newport, M. E. A. (1987). Bumble Bee Behavior and

Selection on Flower Size in the Sky Pilot , Polemonium viscosum. Oecologia, 74(1), 20–23.

• Goulson, D., Nicholls, E., Botías, C., & Rotheray, E. L. (2015). Bee declines driven by combined stress from parasites, pesticides, and lack of flowers. Science, 347(6229), 1255957. http://doi.org/10.1126/science.1255957

• Harder, L. D. (1986). Effects of Nectar Concentration and Flower Depth on Flower Handling Efficiency of Bumble Bees. Oecologia, 69(2), 309–315.

• Nguyen, H., & Nieh, J. C. (2012). Colony and Individual Forager Responses to Food Quality in the New World Bumble Bee, Bombus occidentalis. Journal of Insect Behavior, 25(1), 60–69. http://doi.org/10.1007/s10905-011-9277-5

• Thomson, J. D., Ogilvie, J. E., Makino, T. T., Arisz, A., Raju, S., Rojas-Luengas, V., & Tan, M.