. 2017 Jan 17;13(1):e1005327. doi: 10.1371/journal.pcbi.1005327

Table 2. Model calibration.

This follows conventional population genetic methodology and is achieved by assigning the fitness of each genotype at each locus, assuming that Locus 1 encodes resistance to insecticide A and Locus 2 encodes resistance to insecticide B. The symbols ‘w’ define the genotype fitnesses whose superscripts indicate the genotype (SS, RS, RR) and the locus at which it is located (1, 2) and whose subscripts (-/a/A/b/B) indicate the niche in which fitness is defined where ‘-‘ is insecticide-free and a/A and b/B indicate the presence of insecticides a/A or b/B respectively, in high (upper case) or low (lower case) concentration,. These fitnesses are determined by the effectiveness of the insecticides φ, (i.e. the proportion of SS genotypes killed after contact with the insecticide); setting φ <1 allows a proportion of SS genotypes to survive contact with the insecticide, h is the dominance coefficient, s is selection coefficient favouring IR, and z is fitness cost of carrying resistance alleles in the absence of insecticide.

Genotype	Locus	Insecticide present
Genotype	Locus	-	a	A	b	B
SS	1	$w_{-}^{S S 1} = 1$	$w_{a}^{S S 1} = 1 - φ_{a}^{S S 1}$	$w_{A}^{S S 1} = 1 - φ_{A}^{S S 1}$
RS	1	$w_{-}^{R S 1} = 1 - h_{-}^{1} z_{-}^{R R 1}$	$w_{a}^{R S 1} = w_{a}^{S S 1} + h_{a}^{} s_{a}^{R R 1}$	$w_{A}^{R S 1} = w_{A}^{S S 1} + h_{A}^{} s_{A}^{R R 1}$
RR	1	$w_{-}^{R R 1} = 1 - z_{-}^{R R 1}$	$w_{a}^{R R 1} = w_{a}^{S S 1} + s_{a}^{R R 1}$	$w_{A}^{R R 1} = w_{A}^{S S 1} + s_{A}^{R R 1}$
SS	2	$w_{-}^{S S 2} = 1$			$w_{b}^{S S 2} = 1 - φ_{b}^{S S 2}$	$w_{B}^{S S 2} = 1 - φ_{B}^{S S 2}$
RS (SR)	2	$w_{-}^{R S 2} = 1 - h_{-}^{2} z_{-}^{R R 2}$			$w_{b}^{R S 2} = w_{b}^{S S 2} + h_{b}^{} s_{b}^{R R 2}$	$w_{B}^{R S 2} = w_{B}^{S S 2} + h_{B}^{} s_{B}^{R R 2}$
RR	2	$w_{-}^{R R 2} = 1 - z_{-}^{R R 2}$			$w_{b}^{R R 2} = w_{b}^{S S 2} + s_{b}^{R R 2}$	$w_{B}^{R R 2} = w_{B}^{S S 2} + s_{B}^{R R 2}$