Modeling population dynamics of Eotetranychus kankitus in peach orchards: The role of varietal effects

In this study, we adapted a physiologically structured model based on ordinary differential equations, derived from Rossini’s general framework, to describe the population dynamics of Eotetranychus kankitus in four peach varieties (Oro Azteca, Diamante Mejorado, Arkansas, and F70) under real field conditions in Tepeyahualco, Puebla, México. During the 2024 growing season, 19 samples were collected, yielding the mean mites-per-leaf abundance. The thermal functions for development, fecundity, and mortality were fitted using published laboratory data for E. kankitus , whereas five key reproductive parameters that define the thermal fecundity curve ( a β , b β , k β ), the relative fecundity of mated females ( c 2 ), and the transition from mated to unmated females ( G 1 ← 2 ) were estimated using Bayesian inference. The estimate was obtained using an affine-invariant ensemble sampler Markov Chain Monte Carlo implemented in the emcee library. The overall results provided a satisfactory representation of population abundance; however, variety-specific calibrations revealed biologically and statistically significant differences in reproductive parameters. In particular, cultivar-specific estimates revealed clear differences in parameters governing reproductive state: Arkansas exhibited higher values of the relative fecundity of mated females ( c 2 ) and the transition rate from mated to unmated females ( G 1 ← 2 ), whereas consistently lower values were inferred for F70, indicating reduced reproductive output across the season. These findings demonstrate that peach variety is a key determinant of E. kankitus population dynamics and that accounting for varietal differences through cultivar-specific parameter calibration substantially enhances the model’s predictive performance. This study constitutes one of the first cultivar-scale calibrations for E. kankitus and establishes a methodological framework that integrates physiological data, field observations and Bayesian inference to support pest forecasting and management in fruit tree systems. • Field monitoring and physiological modeling of Eotetranychus kankitus in peach orchards. • Temperature-dependent ODE model (Rossini framework) for development, fecundity and mortality. • Bayesian MCMC estimation of five key reproductive parameters from field data. • First use of affine-invariant MCMC in a tetranychid field population model. • Peach variety identified as a key factor shaping population dynamics.