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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Research Project #435632

Research Project: Extending a Model of Gene Flow by Insect Pollinators to Discontinuous Landscapes

Location: Vegetable Crops Research

Project Number: 5090-21000-068-013-I
Project Type: Interagency Reimbursable Agreement

Start Date: Sep 1, 2018
End Date: Aug 31, 2023

The overall goal of this project is to gather empirical data on the decision making process of three bee species when moving among patches and to incorporate this information into the gene flow model for insect pollinators developed for continuous landscapes to extend the mode to discontinuous landscapes. The specific objectives are 1) to determine the decision making process of three distinct bee species when moving among patches, 2) to use the information collected in #1 to extend the model of gene flow by insect pollinators from continuous to discontinous landscapes and, 3) to test the discontinuous gene flow model using gene flow data collected experimentally.

Models will be developed that describe potential bee decision making process for selecting a patch. For example, choice of a patch may be random, based on nearest neighbor, or on optimal foraging, where both patch size and isolation distance between patches are considered. Simulations of bees moving among patches following the rules of each specific model will generate expectations for the number of transitions expected under each model. Experiments will be set up at four distinct sites to gather data on bee transitions between a center patch (RR alfalfa) and peripheral patches of conventional alfalfas of distinct sizes and isolation distances from the center. The behavioral data will be compared to expectations from the different models to identify the decision model used by each of the three bee species, the common eastern bumble bee, Bombus impatiens, the European honey bee, Apis mellifera, and the alfalfa leafcuttting bee, Megachile rotundata. One bee species will be used per year and its decision making process identified. The information will be incorporated into the model of gene flow within a continuous landscape, developed in our previous NIFA-BRAG grant, to extend the model to discontinuous landscapes. The gene flow model will be tested, for each bee species, using RR seeds collected in the peripheral patches in addition to gene flow data from feral alfalfa populations and from alfalfa seed production fields.