Climate-Driven Phenology and Multigenerational Dynamics of Corythucha arcuata (Heteroptera: Tingidae), and Implications for Sustainable Oak Forest Management

This study presents an integrated analysis of climate-driven phenology and infestation dynamics of the invasive oak lace bug ( Corythucha arcuata ) in foothill oak ecosystems of Rășinari, Romania. Using reconstructed microclimatic data for 2024–2025, systematic field monitoring, degree-day (GDD) modeling, and the De Martonne aridity index, we assessed the combined effects of thermal accumulation and hydric stress on multigenerational development. Results indicate that warm springs and sustained summer temperatures enabled the completion of two full generations (G 1 –G 2 ) in both years, while recurrent late-summer aridity intensified foliar vulnerability and accelerated nymphal development. A third generation (G 3 ) was initiated but remained incomplete due to declining autumn temperatures and photoperiod constraints. Strong habitat-specific differences were observed: exposed forest-edge stands exhibited the highest damage levels (up to 90%), whereas closed-canopy stands benefited from microclimatic buffering. The combined GDD–aridity framework showed close agreement with observed phenological transitions, providing a robust tool for identifying high-risk infestation periods. Climatic projections for 2026 suggest further advancement of generational timing under continued warming and increasing aridity. These findings highlight the growing climatic suitability of foothill oak ecosystems for C. arcuata and support the development of early-warning systems and adaptive strategies for sustainable oak forest management.