Wild bee abundance and diversity was studied in relation to landscape factors surrounding 10 vegetable farms in central and eastern Iowa. Over 800 wild bees from 7 families were collected using pan traps and sweep netting. GIS was used to calculate the percentage of natural landscape on each farm and within a 1km radius. Results showed that farms with a higher percentage of natural landscape on the farm property had greater wild bee abundance and diversity. However, the percentage of natural landscape surrounding the farms did not significantly impact wild bee abundance. This research suggests that wild bee populations can still thrive even with low natural landscape surroundings, which is important for Iowa farmers and agriculture.

1. Wild Bee Abundance and Diversity in
Relation to Landscapes Surrounding
Iowa Vegetable Farms
Jarrett Jensen

2. Introduction
• Iowa vegetable farmers rely heavily on pollinators to produce
crop
• Wild pollination is free but bee diversity and abundance is
declining
• As a result farmers are looking for new ways to prevent this
• There is also not much data on where wild bees are or how
they are being affected
• The landscape on and surrounding the farms can have major
affects on the bees
• We looked at the impact of landscape factors on wild bee
abundance and diversity at vegetable farms in central and
eastern Iowa

3. Methods: Catching the Bees
• Setup pan traps on each farm
• Put colored cups into the traps and filled with soapy water
• Sweep net for 20 minutes on the farm
• Came back to collect the colored cups after a 24 period
• Repeated this process every 2 weeks

4. Methods: Processing Bees
• Removed the bees from the cups and washed with water and
ethanol
• Dried the bees with a hairdryer
• Pinned the bees
• Identified the bees

5. Methods: GIS/GPS
• Mapped out each farm using GIS program and was able to
identify the surrounding landscape of each farm
• Used the GPS to define the landscape that was on each farm
• Used GIS program to calculate landscape percentages both
within the farm boundary, and within a 1-km radius of the
farm (the approximate foraging distance of large bees)

6. GIS/GPS

7. Results
• Total number of Bees caught = 809
• 7 different families
• 10 different farms(5 in the Des Moines area, 3 in Iowa City
Area, 2 North of Cedar Falls Area)
• 3 different collections from each farm

8. Results
Farm 1
Farm 2
Farm 3
Farm 4
Farm 5
Farm 6
Farm 7 Farm 8
Farm 9
Farm 10
0
50
100
150
200
250
0 10 20 30 40 50 60 70 80 90 100
TotalNumberofBees
Percent of Natural Landscape on Farm
Total Number of Bees vs. Percent of Natural
Landscape on the Farm

9. Results
Farm 1
Farm 2
Farm 3
Farm 4
Farm 5
Farm 6
Farm 7 Farm 8
Farm 9
Farm 10
0
50
100
150
200
250
0 5 10 15 20 25 30 35 40 45
TotalNumberofBees
Percent of Natural Landscape Surrounding Farm
Total Number of Bees vs. Percent of Natural
Landscape Surrounding Farm

10. Results

11. Conclusions
• The more natural landscape on each farm seemed to favor
wild bee abundance
• Natural landscape surrounding the farms did not seem to have
a significant effect on wild bee abundance
• Wild bee abundance can still flourish with low natural
landscape surroundings
• This is especially important for farmers in Iowa because of the
corn and soybean fields

12. Conclusions
• Higher percentage of natural landscape on the farm seemed
to favor a greater wild bee diversity
• The types of bees found varied from farm to farm with some
of the farms being dominated by very distinct types of bees

13. Acknowledgements
• Thank you to Andrew Ridgway, Ai Wen, and Kenneth
Elgersma for mentoring me through this entire project
and to Ben Nettleton for helping with bee collection and
identification.
• Funding was made possible by the National Science
Foundation and Iowa EPSCoR.
• This opportunity was made possible by the Department
of Biology at the University of Northern Iowa and their
Summer Undergradate Research Program.