Abstract: In order to evaluate the insecticidal activity of 77 species of plants belonging to 39 families, leaf disc spray method, immersion method and spray method were used to determine the insecticidal activity of plant ethanol extracts against Tetranychus urticae, Frankliniella occidentalis (Pergande) and Sitobion avenae (Fabricius), and further determine the efficacy of plants with better insecticidal activity against T. urticae, F. occidentalis and S. avenae. The results showed that Atropa belladonna L., Sphagneticola calendulacea, Hypecoum erectum L., Smilaz china L., Hippophae rhamnoides L., Dianthus chinensisL., Campsis grandiflora and Eupatorium japonicum extracts had high toxic on T. cinnabarinus, with the corrected mortality of more than 70% after 72 h; and the LC₅₀ value was 254, 297, 413, 424, 428, 553, 663, 725 mg/mL, respectively. A. belladonna L. and S. calendulacea extracts had high toxic on F. occidentalis, with the corrected mortality of more than 80% after 72 h; and the LC₅₀ value was 272, 306 mg/mL, respectively. S. china, H. erectum, H. rhamnoides, Incarvillea sinensis Lam., C. grandiflora and E. japonicum extracts had high toxic on F. occidentalis, with the corrected mortality of 70%—80% after 72 h; and the LC₅₀ value was 446, 485, 523, 563, 710, 712 mg/mL, respectively. Reynoutria japonica Houtt.,A. belladonna, Rubus crataegifolius Bge, Kochia scoparia and Stellera chamaejasme L. extracts had high toxic on S. avenae, with the corrected mortality of more than 70% after 72 h; and the LC₅₀ value was 281, 336, 540, 657, 730 mg/mL, respectively. Plants such as A. belladonna, R. japonica, S. calendulacea and S. china have high corrected mortality rates against different tested insects, demonstrating potential insecticidal activity, which is worthy of further study.

Key words: botanical pesticide, Tetranychus urticae, Frankliniella occidentalis, Sitobion avenae, insecticidal activity