Mosquito traits
As selection acts on specific phenotypes, ‘adaptation’ here refers to a change in the thermal tolerance of a specific mosquito trait—an emergent property that reflects underlying changes in the thermal sensitivity of proteins (Somero 1995, 2003, 2010). The critical traits to examine are those with the strongest climate sensitivity and the strongest impact on overall mosquito fitness. We hypothesize that warming temperatures will impose the strongest selection pressure on traits with the lowest thermal optima and critical thermal maxima. For many mosquito species, these traits are adult lifespan and immature survival (reviewed in Mordecai et al. 2019). However, whether these traits also pose the strongest constraints on mosquito fitness and persistence at high temperatures remains poorly understood because prior work has largely focused on mosquito traits related to disease transmission during the activity season, but there may be additional traits that help mosquitoes tolerate thermal extremes. For this reason, we consider several fitness-relevant mosquito life history traits (e.g., survival, development rates, and fecundity). Additionally, we consider various metrics that describe trait thermal tolerance (e.g., time to partial paralysis, known as ‘knockdown time’ at high temperatures, trait performances at high temperatures, and temperatures causing 50% sample mortality) because they may provide differing information on species adaptive potential (Hangartner and Hoffmann 2016). The framework outlined here can be applied to any specific trait and measurement.