Can the same phenological model predict moth population activity in distinct geographical regions of Southern Europe?

In this work, we investigate the prediction capability of a logistic model in forecasting moth phenology of two lepidopteran pest species which are active in two distinct geographical regions in Southern Europe. Male moth phenology of Anarsia lieneatella Zeller (Lepidoptera: Gelechiidae) and Grapholitha molesta Busck (Lepidoptera: Tortricidae) was observed in typical agricultural landscapes located in Calabrian region in Southern Italy (39.28°N, 16.13E) and Veria region in Northern Greece (40.32oN, 022.18oE). Forecasting performances of the logistic model, in predicting adult moth phenology, was further evaluated by using RMSE and Pearson x2 statistics. Adult male moth phenology of A. lineatella appeared quite similar in Southern Italy and Northern Greece and specimen completed 4 flights per year. Statistical results suggest that phenology of A. lineatella could be predicted with high accuracy in both regions by using the same logistic model. Populations of G. molesta depended strongly upon the particular location of research. Moth phenology of G. molesta appeared quite unpredictable by using the same logistic equation in both regions. This deviation could be probably addressed to regional specific population trends, since sample estimates of population sizes for G. molesta varied considerably between the two geographical regions. Current results suggest that it is possible to improve the prediction capability for G. molesta by combining more than one model in respect to generation and/or region. Thus in cases were population dynamics diverge significantly among different geographical regions, the logistic model may yield acceptable projections when a region specific constraint, based on past observations is added, resulting to significantly less prediction error.