Parasitism of Ladybirds by Hesperomyces in the Canary Islands

Between 2016 and 2022, the ladybird (Coleoptera: Coccinellidae) fauna was surveyed on seven main islands of the Canary Islands archipelago. Adult specimens were collected and screened for thalli of Laboulbeniales (Ascomycota: Laboulbeniomycetes). Altogether, 9,807 ladybird specimens belonging to 39 species were screened, of which 103, representing 10 species, were infected by Laboulbeniales of the genus Hesperomyces . Morphological and molecular examination allowed to distinguish at least seven host-specific Hesperomyces species belonging to three groups: He. virescens species complex (associated with Adalia decempunctata, Harmonia axyridis, Hyperaspis vinciguerrae, Novius cruentatus, Parexochomus nigripennis , and P. quadriplagiatus ), He. coccinelloides species complex ( Scymnus nubilus, Sc. subvillosus durantae , and Stethorus tenerifensis ), and a species (on Nephus flavopictus ) that cannot be assigned to either of the above species complexes or the currently described species in the genus. The most widespread and abundant species was Hesperomyces ex St. tenerifensis ; it was recorded on all seven islands with prevalence rates ranging between 0.04 and 0.19.