Understanding interactions between herbivores and parasitoids is essential for successful biodiversity protection and monitoring and for biological pest control. Morphological identifications employ insect rearing and are complicated by insects’ high diversity and crypsis. DNA barcoding has been successfully used in studies of host–parasitoid interactions as it can substantially increase the recovered real host–parasitoid diversity distorted by overlooked species complexes, or by species with slight morphological differences. However, this approach does not allow the simultaneous detection and identification of host(s) and parasitoid(s). Recently, high-throughput sequencing has shown high potential for surveying ecological communities and trophic interactions. Using mock samples comprising insect larvae and their parasitoids, we tested the potential of DNA metabarcoding for identifying individuals involved in host–parasitoid interactions to different taxonomic levels, and compared it to standard DNA barcoding and morphological approaches. For DNA metabarcoding, we targeted the standard barcoding marker cytochrome oxidase subunit I using highly degenerate primers, 2*300 bp sequencing on a MiSeq platform, and RTAX classification using paired-end reads. Additionally, using a large host–parasitoid dataset from a Central European floodplain forest, we assess the completeness and usability of a local reference library by confronting the number of Barcoding Index Numbers obtained by standard barcoding with the number of morphotypes. Overall, metabarcoding recovery was high, identifying 92.8% of the taxa present in mock samples, and identification success within individual taxonomic levels did not significantly differ among metabarcoding, standard barcoding, and morphology. Based on the current local reference library, 39.4% parasitoid and 90.7% host taxa were identified to the species level. DNA barcoding estimated higher parasitoid diversity than morphotyping, especially in groups with high level of crypsis. This study suggests the potential of metabarcoding for effectively recovering host–parasitoid diversity, together with more accurate identifications obtained from building reliable and comprehensive reference libraries, especially for parasitoids.

Leaf miners are endophagous insect herbivores that feed on plant tissues and develop and live enclosed between the epidermis layers of a single leaf for their entire life cycle. Such close association is a precondition for the evolution of more intimate host-microbe relationships than those found in free-feeding herbivores.

Freshwater diversity is declining at an alarming rate worldwide, and climate change is a key driver. However, attributing biological shifts solely to climate warming remains challenging because of confounding anthropogenic stressors. Peatbogs, being highly conserved, strictly protected, and minimally disturbed, offer a unique study system to isolate climate effects. We compared odonate assemblages in 27 Central European raised and transitional bogs between two sets of standardized surveys approximately 20 years apart (1998–2006 and 2020–2024). During this period, the mean annual air temperature has increased by 1.23°C. We tracked species richness, composition, taxonomic diversity, and functional traits (thermal tolerance, conservation value indicators, and selected morphological and life‐history traits) and also examined phylogenetic patterns of species turnover. Although species richness remained stable, assemblage composition shifted markedly from cold‐adapted, vulnerable bog specialists toward warm‐adapted habitat generalists with lower conservation value. Notably, Ponto‐Mediterranean species and those with a lower upper elevational limit increased their occupancy. Although the phylogenetic signal across the evolutionary tree of odonates was low, implying that the responses of the species to climate change were independent of their phylogenetic position, we revealed frequent genus‐level replacements. These findings reinforce the position of odonates as a model group for detecting climate‐driven changes in freshwater communities. Our study has revealed that climate warming alone can trigger profound reorganization of insect communities in inherently stable peatbog habitats. Specific traits linked to vulnerability (e.g., thermal index, red list status) and specialization proved to be promising predictors of future shifts in odonatofauna of temperate peatlands. The pronounced changes documented here may precede irreversible transformations of these unique ecosystems, highlighting the urgency of monitoring bog habitats and maintaining their stability under ongoing global change.