Level of host concealment shape parasitoid community of microlepidopteran species living on hops

1. BackgroundParasitoid-host interactions are key drivers of insect community structure, with host concealment influencing parasitoid diversity and parasitism rates. However, the effectiveness of different host defense strategies against parasitoids remains insufficiently understood. 2. ObjectiveThis study examines how host concealment level affects parasitoid communities and parasitism rates in two microlepidopteran species developing on hops (Humulus lupulus L.), Caloptilia fidella and Cosmopterix zieglerella, which employ leaf-rolling and leaf-mining strategies, respectively. 3. MethodsWe combined morphological identification with molecular species delimitation using ITS2 and CO1 markers and applied ASAP and bPTP methods to refine parasitoid taxonomy and detect cryptic species. 4. ResultsSemi-concealed C. fidella larvae in leaf rolls experienced significantly higher parasitism than their mining stages, whereas fully concealed C. zieglerella had lower parasitism rates. Molecular analyses confirmed the idiobiont strategy in Sympiesis acalle, S. sericeicornis, and Elachertus fenestratus, and bPTP proved more sensitive in detecting cryptic species than ASAP. 5. SignificanceThese findings demonstrate that semi-concealed hosts face a higher risk of parasitism than fully concealed hosts, suggesting that leaf-mining provides better protection than leaf-rolling in studied hosts. The study also highlights the power of molecular tools in species delimitation, emphasizing their importance for refining parasitoid taxonomy and advancing our understanding of host-parasitoid interactions.