Trophic dynamics of cicada nymphs after severe wildfires: The importance of resprouting plant species

Wildfires significantly affect soils and vegetation in natural ecosystems, altering trophic interactions and nutrient cycling. This study investigates the trophic dynamics of cicada nymphs ( Cicada orni ), strictly dependent on plant roots for nutrition during their hypogeal phase, in two severe wildfire-affected regions of north-eastern Iberian Peninsula. For this, stable isotopes (δ¹³C and δ¹⁵N) were analysed on cicada exuviae and host plant databases collected from burnt and unburnt areas over a decade. The results show shifts in cicada isotopic signatures influenced by plant regeneration strategies and changes in soil properties. Resprouting species, such as Genista scorpius , emerged as important post-fire food resources. Significant temporal and spatial variations in isotopic values underline the role of fire in shaping belowground trophic dynamics. These findings emphasize the importance of plant resilience mechanisms in sustaining herbivorous insect populations and contribute to the understanding of post-fire ecological recovery and management in Mediterranean ecosystems. • Belowground cicada nymph diet shifts after wildfires. • Cicada isotopic values can depend on plant root availability and soil conditions. • Stable isotope data reveals cicada responses to fire-driven disturbances. • Cicada emergence links below- and aboveground isotopic signals.