Can Wild Bees Meet Pollination Needs in Apples?: Determining the Efficacy of Native Bees and Their Contribution to Pollination

Project Overview

Project Type: Graduate Student
Funds awarded in 2010: $9,850.00
Projected End Date: 12/31/2014
Grant Recipient: University of Wisconsin
Region: North Central
State: Wisconsin
Graduate Student:
Faculty Advisor:
Claudio Gratton
University of Wisconsin, Dept. Entomology

Annual Reports


  • Fruits: apples, cherries, general tree fruits


  • Education and Training: on-farm/ranch research
  • Natural Resources/Environment: biodiversity, wildlife

    Proposal abstract:

    Apples are a pollinator-dependent crop grown throughout much of north-central USA. Historically, growers have relied on honey bees to meet the pollination requirements of the crop. However, as honey bees become more expensive and difficult to obtain, the relative importance of native, wild pollinators increases. While recommendations exist for the number of honey bee hives needed for crop pollination, the number or types of wild bees required for apple pollination or the relative efficacy of these bees is not known. This research will help answer the question of whether wild bees alone can provide full pollination and will aid growers in evaluating their own wild bee community. Specifically, I propose to 1) assess which wild bees are most efficient in apples, 2) determine whether wild bees alone, and in what numbers, can provide full pollination for apples, and 3) develop a field ID guide of effective apple pollinators. Pollination rates will be examined at orchards with and without honey bees, and varying in abundance of wild bees. Research results and the pollinator ID guide will be shared at grower meetings and online. Growers will be able to evaluate their wild bee community with the field ID guide, thus enabling them to assess the degree of pollination freely provided by wild bees. Furthermore, with a better understanding of which wild bees contribute to apple pollination, growers can tailor their management for the preservation of these bees. This research will be evaluated through discussions and surveys with participating orchards and members of the Eco-Apple Networks as well as through pre and post-presentation questionnaires.

    Project objectives from proposal:

    The research will have three main objectives: (1) assess which wild bees are the most efficient pollinators of apples, (2) determine whether wild bees alone, and in what numbers, can provide full pollination for apples, and (3) develop a field ID guide to effective apple pollinators.

    The overall aim of this research is to help growers determine the contributions of wild bees to pollination of apples, thereby decreasing their dependence on honey bees. The primary audience for this research is apple growers in Wisconsin and throughout the North Central Midwest where bee communities are similar. Additional audiences include growers of other pollinator-dependent fruit, and organizations and researchers that study wild bees. Ultimately, the research developed in this proposal can help growers understand to what extent native bees provide free pollination services and help them evaluate and monitor their own pollinator community the same way that they may scout and monitor pest activity.

    The short-term outcomes will include increased grower knowledge of which wild bees are the most efficient pollinators of apples and how these wild bees compare to honey bees. Our research will also determine if orchards without managed honey bees can obtain pollination levels comparable to orchards with honey bees. Growers will furthermore have an increased understanding of the numbers and diversity of wild bees needed for adequate pollination and will have resources to identify wild bees in their orchards.

    An intermediate outcome will be that growers can assess the wild bee community in their orchards and monitor over time. With information on the relative efficacy of different bees, growers can make management decisions to conserve these efficient pollinators by providing specific floral and nesting resources. In the long-term, growers can make more informed decisions on whether they need to rent or manage bees to augment their wild bee community. Researchers can use the information generated from this study to work towards developing a threshold for wild bees above which growers can expect to receive adequate pollination. Additionally, an increased reliance on wild bees could result in increased participation in bee conservation efforts. Finally, a reduced dependency on honey bees may make apples a more sustainable and profitable crop.

    Results from this research will be presented to apple growers through grower meetings and networks. Previous research has been presented at the Wisconsin Fresh Fruit and Vegetable Conference and at meetings of the Eco Apple Network. The pollinator ID guide will be distributed to growers at these meetings. Additionally, research results and the ID guide will be available online at extension websites. Furthermore, this research will be presented to other organizations and individuals studying bees at entomology and ecology conferences and will be published in peer-reviewed articles.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.