Figure 3.

The intrinsic rate of increase, λ, a measure of fitness, for mosquitoes with a nocturnal (sensitive) biting pattern and mosquitoes with a crepuscular biting pattern (resistant), by coverage level of bed nets, ${\mathit{\varphi }}_b$. The dashed and dotted lines divide the parameter space into levels of ${\mathit{\varphi }}_b$ where the nocturnal pattern has a greater fitness than the crepuscular pattern (λ _n > λ _c), an area of coverage where selection favors the crepuscular pattern (λ _c > λ _n), and higher levels of coverage where λ of both types is below one and neither type will persist.