Abstract: 【Aim】 The English grain aphid, Sitobion avenae, is a severe agricultural pest in China. This study aims to elucidate the interfering effects of miR-14 antagomir on the population of S. avenae, providing a novel technical reference for its prevention and control. 【Methods】Employing a nanomaterial/adjuvant delivery system as the carrier, 0.2 μL of 300 nmol/L miR-14 antagomir was administered to the 1st instar nymphs of S. avenae newborn within 24 h with topical application. Concurrently, nano-material/adjuvant negative control (NNC) and water negative control (WNC) groups were established. The parameters including the proportion of winged morphs, nymphal duration, adult longevity, total developmental duration, mean longevity, reproductive period, number of nymphs produced per female, pre-adult survival rate, total pre-nymphal period and adult pre-nymphal period were calculated. The effects of miR-14 antagomir on the growth, development and fecundity of S. avenae were analyzed using the age-stage, two-sex life table. 【Results】miR-14 antagomir had a significant inhibitory effect on the population of S. avenae. Treatment with miR-14 antagomir resulted in a significant decrease in the pre-adult survival rate and the proportion of winged morphs of S. avenae compared to the controls NNC and WNC. In the miR-14 antagomir treatment, the duration of the 1st instar nymphs of S. avenae was significantly prolonged by 0.17 and 0.29 d, respectively, and that of the 2nd instar nymphs was significantly prolonged by 0.24 and 0.25 d, respectively, as compared to that in the controls NNC and WNC. The mean longevity of S. avenae treated with miR-14 antagomir was significantly shortened by 4.05 and 4.72 d, respectively, as compared to that of the controls NNC and WNC. The adult pre-nymphal period of S. avenae treated with miR-14 antagomir was extended by 0.27 and 0.22 d, respectively, and the total pre-nymphal period of S. avenae treated with miR-14 antagomir was extended by 0.53 d in comparison to those in both the controls NNC and WNC. In addition, the intrinsic rate of increase (r), net reproductive rate (R₀), and finite rate of increase (λ) of S. avenae treated with miR-14 antagomir were significantly decreased as compared to those of the controls NNC and WNC. After treatment with miR-14 antagomir, the population size of S. avenae was approximately 0.33 million after 60 d, significantly lower than that of the controls NNC and WNC (3.24 million and 4.42 million, respectively). 【Conclusion】 miR-14 antagomir prolongs the duration of low instar nymphs, reduces the proportion of winged morphs and inhibits the population growth of S. avenae. These findings provide valuable insights for developing miRNA-based nucleic acid pesticides against S. avenae.

Key words: Sitobion avenae, miR-14 antagomir, two-sex life table, growth and development, population parameters