In response to numerous inquiries, listed below are past survey findings on the foraging behavior of bees on various native Upper Midwest prairie forbs.

These surveys were conducted at native plant nurseries in southern Wisconsin over a 2-year period. Because the plants are grown as large-scale monoculture row crops, under artificial conditions (using center-pivot irrigation, etc.), any information represented here may not necessarily reflect natural foraging preferences. That said, anecdotal observations in natural areas tend to confirm most of these findings.

It is also worth noting that these nurseries are stocked with limited numbers honey bees, and small numbers of alfalfa leafcutter bees, and bumble bees at various locations. Honey bees are obviously over-represented in the survey, however the Bombus and Megachile species recorded included good numbers of wild, non-managed bees.

Finally these surveys were conducted in the course of regular crop pest and disease scouting work, and therefore represent a “research byproduct." A more comprehensive bee survey might produce different results.

Thank you for all of your interest!
Eric Mader
April 21, 2008

 

Dominant Bee Families of Prairie Forbs (2006 and 2007)
This survey consisted of 90 common prairie forbs, each monitored over several days during the week of peak bloom. Bee counts were made on a number of sample plants in each field, and tallied according to family.

 

Average Bee Density per Plant at Peak Bloom (2006)
Average Bee Density per Plant at Peak Bloom (2007)
The plants included in these lists are 35 of the more commonly recommended species for native pollinators (according to various conservation group publications, as well as personal anecdotes). Bee counts were performed on a number of sample plants over two days during peak bloom, and averaged for a “bees per plant” number.

This approach deviates from sample sizes used in other pollinator studies (such as “bees per square meter”), but again, these surveys were conducted in the course of routine crop scouting duties. Please also note that in many cases large numbers of non-bee pollinators were present on some of these plants, so their over all value to a variety of pollinators is not necessarily represented here.   

 

Establishing Pollinator Meadows
This is a document was prepared for a Wisconsin hobby beekeeping group in 2007. As with the other documents here, this might be helpful to a number of people interested in pollinator conservation efforts.

It covers the basics of prairie plant establishment from seed, including: site selection, seedbed preparation, broadcast versus drill seeding, and long-term maintenance.

The emphasis is on large-scale plantings (as opposed to small urban butterfly gardens), and includes a fairly detailed discussion on the selection and use of appropriate agricultural field implements.

For more detailed information on the conservation of native pollinators, including many free fact sheets, please visit the Xerces Society for Invertebrate Conservation.