Climatic seasonality shapes insect community composition on the Mongolian Plateau

• Seasonal climate variability shapes insect diversity in grassland ecosystems. • Precipitation and temperature seasonality are key drivers of insect abundance. • Climate effects are mediated by vegetation cover and soil properties. • PCA and PLS-PM reveal direct and indirect drivers of community composition. • Findings inform adaptive strategies for biodiversity under climate change. Insects, as key components of steppe ecosystems, play an essential role in maintaining biodiversity. However, while climate change is recognized as a major factor in steppe degradation and biodiversity decline, the specific mechanisms by which climatic seasonality impacts insect community structure and composition remain poorly understood. To explore this, we conducted a field survey of insect communities across 66 sample plots on the Mongolian Plateau, analyzing climate variables (e.g., annual precipitation, temperature), vegetation status (NDVI), and soil characteristics. Our results indicated that climate, particularly seasonal shifts in precipitation and temperature, were primary factors shaping insect communities. Specifically, precipitation – annual, wettest quarter and warmest quarter – significantly influenced insect abundance and community composition, while temperature seasonality and isothermality were the key drivers of diversity Margalef index. Meanwhile, vegetation status, represented by the NDVI, emerged as a critical factor for overall insect diversity. Moreover, our findings suggested that climate, vegetation, and soil factors collectively influence species richness, providing important insights for steppe biodiversity conservation. Understanding these relationships is essential for developing adaptive conservation strategies under changing climatic conditions.