Development Rate of the Larvae of the Mosquito Aedes albifasciatus: A Mathematical Model as Decision Tool

The flood mosquito Aedes albifasciatus adapts to the thermal conditions of different regions and presents demographic explosions, causing problems for livestock farming and public health, including outbreaks of western equine encephalitis. Between October 2019 and June 2021, their larval development was monitored in Tandil temporary pools, recording 35 events. For each one, the larval development time and the average daily mean temperatures were calculated. The data were fitted to several temperature-dependent bibliography nonlinear models for insects, previously setting the lower and upper thermal development thresholds (for Ae. albifasciatus in the studied region) at 7.62°C and 33°C, respectively. A new model, based on combinations of factors present in bibliography models, is proposed to estimate the larval development rate as a function of temperature. The models were validated using the root mean square error (RMSE) and concordance index (d). In addition, the distribution of percentage frequencies of the difference between the length of the period estimated by the models and that recorded in the field was calculated. The best model had the highest agreement index (0.9), the lowest RMSE (0.01), and the highest agreement between the estimated and observed development rate (83%). This model could be useful as a pre-diction tool of Ae. albifasciatus abundance peaks in the context of future outbreaks of western equine encephalitis in South America.