Phenological responses and a comparative phylogenetic insight of Anarsia lineatella and Grapholita molesta between distinct geographical regions within the mediterranean basin

A unique logistic model for predicting population dynamics of Anarsia lineatella and Grapholita molesta was evaluated on populations sampled from Italy and Greece. Intraspecific mtDNA divergence was additionally estimated in an effort to examine whether regional differences in moth
phenologies are associated with genetic divergence. A. lineatella populations
displayed closer similarities on phenological responses between the two observation regions. As a result, population fluctuations in bothregions could be accurately predicted based on the constructed model.
However, that was not the case for G. molesta as its populations exhibited a more regional behaviour, and thus, the model was less accurate. It is notable that degree-day accumulations above the lower temperature thresholds were recorded in Italy on month earlier than in Greece (1st
March in Calabria in contrast to 1st April in Veria). That kind of observed deviations in moth phenologies could be potentially attributed to regional environmental conditions or even genetic differentiation. Despite the low number of individuals analysed, this first attempt to study the levels of
intraspecific divergence between Italian and Greek moth populations revealed that both species exhibit evidence of regional-based separation.
Our study provides the first comprehensive phenological comparison between populations of A. lineatella and G. molesta from Italy and Greece.
At the same time, the population genetic structure data reveal differentiation
between these two regions for both species, something that should be further investigated as it could provide a possible explanation for the observed phenological differences. Moreover, DNA barcoding confirmed that G. molesta pheromone blends attracted at least two morphologically
close-related tortricid moth species. This fact probably explains the phenological
variations observed for this species as well as the difficulties in defining the number of non-overlapping flights.