Dispersal at multiple scales and the evolution of resistance: Leaf beetles enter the matrix.
Baker, Mitchell*,1, 1 Biology Department, Flushing, NY, 11367
ABSTRACT- Dispersal and the resulting gene flow generally acts to homogenize populations and reduce local adaptation. This process is the theoretical basis for the primary method currently proposed for managing the evolution of resistance to insecticides. Agricultural refuges are areas left untreated to preserve alleles for susceptibility. All transgenically modified insecticidal crops are required to be planted along with refuges of conventional plants. However, there are no requirements regarding the spatial arrangement of refuges and treated areas. I present a model of resistance evolution in landscapes composed of treated and untreated cultivated areas, and untreated matrix with a low density of hosts. Depending on the scale of movement the presence of matrix between refuges and treated areas can eliminate or enhance the refuge effect. The presence of a dispersal polymorphism increases the complexity of the relationship between optimal refuge scale and movement, but can greatly enhance refuge effectiveness.
Key words: leptintarsa decemlineata, refuge, insecticide, resistance evolution
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