Seasonal, Aspect and Elevational Effects on Auchenorrhyncha Communities in Taibai Mountain, China

Forest biomes exhibit considerable spatial heterogeneity in insect diversity, hosting complex and dynamic insect assemblages. Auchenorrhyncha, a highly diverse infraorder of herbivorous hemipterans, demonstrates strong associations with native flora and exhibits predictable responses to environmental changes, rendering this group an ideal bioindicator for ecosystem health assessments. While the utility of these insects has been recognized in grassland ecosystems, their utility for monitoring montane forests remains underexplored. This study investigates the spatiotemporal and elevational distribution patterns of Auchenorrhyncha on Taibai Mountain, a critical biodiversity hotspot within China's Qinling Range. Systematic field surveys conducted along a continuous elevational gradient (1100 to 3700 m a.s.l.) documented a total of 124 species belonging to 80 genera and 12 families. Notably, species richness was significantly higher on the southern slope (95 species/60 genera) than on the northern slope (71 species/51 genera). Clear elevational stratification was observed: Cicadellidae and Aphrophoridae were widely distributed, whereas Fulgoroidea and Membracidae were restricted elevations below the Betula utilis zones, and Cicadidae occurred exclusively in Quercus variabilis and Q. aliena forests. Community diversity peaked at mid-elevations, consistent with the mid-domain effect, and was highest in Q. aliena forests. Community similarity was greater within the same forest type across different slopes than between adjacent elevational zones on the same slope. Seasonal analysis revealed peak diversity in July, with the southern slope consistently supporting higher diversity across all sampling periods. These findings not only establish essential baseline data but also confirm the potential of Auchenorrhyncha as effective bioindicators for monitoring biodiversity and ecological changes in complex montane ecosystems.