Sublethal and intergenerational effects of flonicamid on biological traits in the rose-grain aphid, Metopolophium dirhodum.

Abstract

The rose-grain aphid, Metopolophium dirhodum (Walker), has been identified as a predominant aphid species in wheat agroecosystems. Flonicamid, a novel pyridinamide insect growth regulator, has demonstrated high efficacy against various sap-sucking pests. We investigated the sublethal and intergenerational effects of flonicamid on M. dirhodum using life table analysis. We found that flonicamid had a certain degree of acute toxicity to M. dirhodum. Exposure to sublethal concentrations of flonicamid (LC15 and LC35) significantly reduced adult longevity, reproductive duration, and fecundity in the F0 generation of M. dirhodum. Moreover, these sublethal concentrations adversely affected the F1 generation, decreasing fecundity and altering key life table parameters, including adult longevity, total longevity, reproductive period, adult pre-reproductive period, nymph production per female, age-stage-specific survival rate (sxj), intrinsic rate of increase (r), net reproductive rate (R0), and finite rate of increase (λ). Population projections further demonstrated a significant decline in the total population size of M. dirhodum under sublethal flonicamid exposure compared to the control. These findings demonstrate that flonicamid exerts adverse sublethal and intergenerational effects on M. dirhodum, ultimately suppressing its population growth. The study outcomes provide valuable evidence for evaluating flonicamid's overall pesticidal potential and enhancing integrated pest management protocols for wheat aphid control.