Fig. 3.

Minor costs of resistance. Evolution of the R allele frequency (a), the L allele frequency (b), and the change in the relative population size over time (c). The model is spatial, with release ratio d=20, and a strong partially dominant incomplete resistance (${\gamma }_{\mathit{SR}}=0.2$, ${\gamma }_{\mathit{RR}}=0.1$) with minor costs (${\psi }_{\mathit{SR}}=0.95$, ${\psi }_{\mathit{RR}}=0.85$). Dashed lines indicate the target deme, solid lines indicate the non-target deme, and the line colours indicate the simulated dispersal rate (see legend). The non-target deme acts as a source of S alleles, thereby enhancing the effectiveness of target population control.