Abstract
BACKGROUND: The English grain aphid, Sitobion avenae (Fabricius) (Hemiptera: Aphididae), is a highly detrimental cereal aphid in Western Europe, infesting all cereal crops, including barley, wheat and oats. Pyrethroid pesticides are extensively utilized for the management of S . avenae worldwide. The extended use of pyrethroid pesticides to manage S. avenae has led to the emergence of resistance to lambda‐cyhalothrin. However, a detailed assessment of life‐history traits linked to lambda‐cyhalothrin resistance in S. avenae has not yet been conducted. The objectives of this study were to utilize age‐stage, two‐sex life table theory to examine the life‐history traits of a widespread clonal lineage of S. avenae that exhibits partial resistance to lambda‐cyhalothrin. RESULTS: There was a significant decrease in the relative fitness (0.508) of lambda‐cyhalothrin‐resistant clones (SA3) in comparison to the susceptible clonal lineage (SA27) of S. avenae . The biological parameter data indicated that the SA3 clonal lineage exhibited significantly prolonged developmental stages (excluding N4) and reduced longevity, fecundity, adult pre‐reproductive period, and reproductive days compared to the SA27 clone. By contrast, population growth parameters, including the net reproduction rate ( R 0 ), intrinsic rate of increase ( r ) and finite rate of increase ( λ ), were markedly lower in the SA3 clone than in the SA27 clone of S. avenae . CONCLUSIONS: These data provide comprehensive insights into the life‐history characteristics and population dynamics of the lambda‐cyhalothrin‐resistant clone of S. avenae , which may be fundamental for development of decision support tools and resistance management measures against this pest. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.