Peatland and forest edges influence the abundance of Gondwanan moss bugs (Hemiptera: Peloridiidae) in threatened South American wetlands

• Moss bug Peloridium pomponorum is limited to Sphagnum in peatlands and forests. • Abundances differ across stages of life, ecosystems, habitats and seasons. • Edge habitat is the strongest predictor of adult, nymph, and total abundance. • Limited range and poor-quality habitat suggest a vulnerable status. • Protecting peatlands and Sphagnum-related forests, especially edges, is essential. Peloridiidae, a crucial family for understanding Hemiptera evolution, are insects closely associated with bryophytes, earning them the common name “moss bugs.“ Peloridium pomponorum is a moss bug limited to Chiloé Island (Chile) and mainly inhabits Sphagnum in glaciogenic and anthropogenic peatlands, as well as in Metrosideros stipularis forests —ecosystems increasingly threatened by human activities. To study its habitat use and conservation status, we sampled 15 sites across Chiloé, recording the numbers of adults and nymphs in relation to habitat type (glaciogenic and anthropogenic peatlands, and forest) habitat zone (edge, intermediate, and core), and season. Abundance patterns were analyzed with Kruskal-Wallis tests and negative binomial generalized linear mixed models to evaluate predictor effects. Results indicate that adult and total abundance were significantly higher in edge habitats, while nymph and total abundances were higher in anthropogenic peatlands. Seasonal variations were observed, with higher nymph and total abundance during summer compared to autumn and winter. Habitat zone, particularly the edge, was the most influential predictor for adults, nymphs, and total abundance. The species’ geographic range is limited (3,654 km2 EOO; 44 km2 AOO), with nine localities and eight subpopulations. Ongoing deforestation and moss harvesting indicate an inferred decline in habitat quality. Analysis from inferred sites of occupancy revealed a severely fragmented distribution, supporting its classification as Vulnerable under IUCN criteria B1ab(iii) + B2ab(iii). Our findings underscore the importance of conserving peatlands and Sphagnum -associated forests, especially edge habitats. Future research should include vegetation structure, microclimate, and adopt adaptive management approaches to guide conservation strategies.