Thermal regimes and life cycles of Serratella ignita (Poda, 1761) (Ephemeroptera: Ephemerellidae) in NW Italy

This study examined the influence of thermal regimes on the life cycle of Serratella ignita (Poda, 1761) (Ephemeroptera: Ephemerellidae) populations in three Alpine rivers (Pellice, Malone, and Stura rivers) in North-West Italy. Monthly samplings were conducted to evaluate life history of mayfly, while river thermal characteristics were monitored using temperature dataloggers. Significant differences were observed among rivers, with variations in nymph occurrence and development speed across the three lotic systems. During a comparable period of nymph abundance in all rivers, the average nymph length in the Malone River was notably greater than in the Pellice and even more so than in the Stura. These variations highlight the crucial role of thermal characteristics in shaping S. ignita's life cycle. The findings confirm the species' high plasticity, enabling it to adapt effectively to diverse environmental conditions. This adaptability underscores S. ignita's value as a model organism for studying aquatic insects under varying thermal conditions. In the context of climate change, with predicted increases in water temperatures in freshwater ecosystems, it is essential to understand how aquatic insects respond to global climate changes. Such knowledge is critical for developing strategies to conserve biodiversity and maintain the ecological integrity of riverine systems.