Will dual fungal infections increase mortality of Harmonia axyridis in natural populations?
Abstract: Reviewing the effects of parasites, pathogens, and parasitoids of Harmoniaaxyridis shows that they have only limited potential for controlling population dynamics oftheir host. Hesperomyces virescens (Ascomycota: Laboulbeniales) and Beauveria bassiana(Ascomycota: Hypocreales) have some negative effects on ladybirds; when acting alone theyonly have limited potential for controlling populations of invasive ladybirds. Independentstudies show that natural enemies are starting to use H. axyridis as a new host. No studieshave focused on the effects of infections of more than one pathogen on H. axyridis. Wedecided to examine mortality of native and invasive ladybirds co-infected with H. virescensand B. bassiana. Given the abundance of both H. virescens and B. bassiana in theenvironment, we predict that invasive populations of H. axyridis will be naturally regulated.