The temperature dependence of maximal population growth rate (rm) is key to predicting ectotherm responses to climatic change. Matrix projection models (MPMs) are used to calculate rm because they can incorporate variation and inherent time-delays in underlying life-history traits. However, MPM calculations can be laborious and do not reflect time’s continuous nature. Ordinary differential equation-based models (ODEMs) offer a relatively tractable alternative, but it is largely unknown whether ODEM-based calculations and MPM broadly agree when environmental variation affects temperature–dependent rm by introducing time-delays and altering juvenile survival trajectories. We investigate differences in predicted temperature-dependent rm from an ODEM with that calculated from MPMs using temperature– and resource-dependent life-history trait data for the mosquito vector, Aedes aegypti. We show that discrete- and continuous-time calculations of temperature-dependent rm can vary with resource availability and are sensitive to juvenile survival characterisations, suggesting ODEMs can provide comparable temperature–dependent rm calculations unless resources are constraining.

Vector-borne diseases cause significant financial and human loss, with billions of dollars spent on control. Arthropod vectors experience a complex suite of environmental factors that affect fitness, population growth, and species interactions across multiple spatial and temporal scales. Temperature and water availability are two of the most important abiotic variables influencing their distributions and abundances. While extensive research on temperature exists, the influence of humidity on vector and pathogen parameters affecting disease dynamics are less understood. Humidity is often underemphasized, and when considered, is often treated as independent of temperature even though desiccation likely contributes to declines in trait performance at warmer temperatures. This Perspectives explores how humidity shapes the thermal performance of mosquito-borne pathogen transmission. We summarize what is known about its effects and propose a conceptual model for how temperature and humidity interact to shape the range of temperatures across which mosquitoes persist and achieve high transmission potential. We discuss how failing to account for these interactions hinders efforts to forecast transmission dynamics and respond to epidemics of mosquito-borne infections. We outline future research areas that will ground the effects of humidity on the thermal biology of pathogen transmission in a theoretical and empirical framework to improve spatial and temporal prediction of vector-borne pathogen transmission.