Assessment of <i>Sitobion avenae</i> (Hemiptera: Aphididae) adaptability to different oat varieties based on the age-stage, 2-sex life table, and electrical penetration graph technology

The deployment of resistant cultivars is an effective strategy for managing cereal aphids. The English grain aphid, Sitobion avenae (Fabricius), is a major pest of oat (Avena sativa L.), significantly affecting both yield and quality. In this study, the aphid resistance levels of oat varieties were evaluated using the aphid quantity ratio method, the age-stage, 2-sex life table, and the electrical penetration graph technique. One oat variety with moderate resistance, 12 with low resistance, 14 with low susceptibility, 6 with moderate susceptibility, and 1 with high susceptibility were identified by the aphid quantity ratio method. Life table analyses showed that aphid individuals feeding on resistant cultivars (Baler II, Longyan No. 4, Baiyan No. 7, Jizhangyan No. 4, and Leader) exhibited prolonged nymphal development duration, reduced fecundity, intrinsic rate of natural increase (rm), and finite rate of increase (λ), compared to those on the susceptible cultivar Longyan No. 3. Electrical penetration graph results demonstrated that aphid individuals on resistant varieties had longer durations of non-probing (Np), pathway (C), and phloem salivation phases, but substantially shorter durations of phloem ingestion (E2). These findings suggest that resistance of oat varieties against S. avenae may occur at the phloem phase. This study provides support for the screening and breeding efforts of aphid-resistant oat cultivars for S. avenae control.