Hawkmoths’ evolutionary history structures plant-pollinator interactions frequency, beyond its effect through ecological traits

Multiple non-exclusive neutral or niche-based processes influence species interactions and shape the structure of ecological networks.Although evolutionary processes may influence interactions via shared inherited traits, their relative importance in comparison to ecological processes remain poorly understood.Here we investigate the effects of evolutionary history compared to ecological processes on both interaction frequencies and the emergence of modularity in a plant-hawkmoth interaction network.Finally, we tested the phylogenetic signals on hawkmoth ecological traits relevant to pollination interactions.We analyzed a planthawkmoth network on Pampa grasslands for which we collected morphological, phenological, abundance and phylogenetic data for every species in the network to evaluate neutral-based processes (i.e., random chance of encounter dictated by species abundances) or niche-based processes (i.e., morphological matching).The best model predicting interactions indicated that, beyond increasing interaction frequencies with increased morphological matching and phenological overlap, distantly related hawkmoth species also tended to interact with plants more frequently.Further, by evaluating whether hawkmoth composition differed among interaction modules, we found that modules encompassed phylogenetically distant and functionally distinct hawkmoth species.Thus, module composition suggests that, despite evolutionary history and ecological traits influencing interactions' frequency, modules emergence may be also potentially modulated by processes such as environmental filtering or stochastic factors acting on other traits than the ones evaluated here.Such processes may have influenced hawkmoths' species composition in the community and ultimately also shape the observed interaction patterns.