Impacts of the invasive hornet Vespa velutina on native wasp species: a first effort to understand population-level effects in an invaded area of Europe

Abstract Invasive alien species could generate a multitude of impacts towards native species. The introduction and spread Vespa velutina in Europe is raising concern for the conservation insect’s biodiversity, including wasps due to predation, competition or combination these two mechanisms. Nevertheless, most evidence negative effects on other are based laboratory experiments, direct observations, considerations about biology ecology Vespidae. No field study explored how abundance V. affect population Vespidae, as expected case predation. We analysed influenced that crabro , 4 years after arrival establishment our area, Italy. Moreover, we compared abundances three Vespidae ( Vespula vulgaris germanica ), between area an adjacent uninvaded with similar environmental conditions. Bayesian Generalized Linear Models revealed was positively associated, where scarce. Covariation disappeared only at those trapping sites extremely abundant. were invaded areas. Implications insect wide-scale monitoring activity performed investigate has not detected any relation presence invasive More effort however requested understanding if really population-level.