Multi-Locus Nuclear Marker Assessment of Genetic Diversity in Swiss Orthoptera Unveils Conservation Status Limitations.

With accelerating biodiversity loss, tracking both inter- and intraspecific diversity is critical, as within-species variation underpins population viability and adaptive potential. We developed a new multi-locus framework, and obtained an Orthoptera-specific marker panel targeting 398 nuclear loci plus the mitogenome and ribosomal DNA to assess species boundaries, population structure and intraspecific diversity. We applied this approach to 645 specimens covering all 105 Swiss Orthoptera species, sampled during the nationwide Red List update. This multi-locus dataset produced a well-supported phylogeny and resolved several taxonomic ambiguities with direct conservation relevance. We demonstrate its ability to identify fine-scale population structure and further illustrate its application to genetic diversity estimation. While species' IUCN threat levels were not correlated with genetic diversity, we found a significant negative association between genetic diversity and dependence on riparian habitats: river-bank specialists showed lower diversity, likely reflecting the severe fragmentation and alteration of these ecosystems. Our results demonstrate that the application of new molecular tools provides valuable, complementary insights not only for taxonomy but also for conservation assessments. The development and application of genetic monitoring frameworks, such as the one presented here, are highly valuable for promoting the inclusion of genetic diversity in future conservation assessments.