The modeling focuses on the global-scale relationships between climate and the development, population dynamics, and potential distribution of the Aedes aegypti mosquito. Many entomological models use day-degree or temperature summation models that assume development rate is proportional to temperature. This suits modeling development within a limited temperature range. In the model, a single rate-controlling enzyme determines development rates. Using the daily mean air temperature, a simplification of hourly water temperatures, we calculate daily development rates, for each cohort in its particular life stage.
Development accumulates each day and is complete when it reaches a specified level.
In order to complete the larval stage, the larva must also reach a minimum weight. As a simplification at the global scale, we assume that food availability is not a limiting factor for larval weight gain and modify the equation accordingly. Daily minimum and maximum temperatures, linearly approximated from the monthly values, determine survivorship rates. These rates are based on laboratory studies and anecdotal field observations, which could vary from what occurs in the field. At temperature extremes we set the survival factor to 0.00, since these studies indicate that mosquitoes at any life stage are unlikely to survive extreme temperatures.