Insecticide screening to control Myzus persicae in tobacco fields and their safety evaluation for Rhynocoris fuscipes.

To screen for effective Myzus persicae control agents that are safe for Rhynocoris fuscipes in tobacco fields, the toxicity of nine common insecticides against M. persicae and 2nd instar nymphs of R. fuscipes was tested using the leaf-dip method and the insecticide residual in glass tube method. Drug safety for R. fuscipes was evaluated, and plot experiments were conducted in tobacco fields. The results showed that the LC₅₀ of the nine agents for M. persicae were acetamidine 44.311 mg/L, fludizonitrile 46.696 mg/L, rotenone 71.499 mg/L, eucalyptol 77.538 mg/L, dipropirenol 139.697 mg/L, pyrazidone 175.142 mg/L, pyrethrin 427.589 mg/L, veratrine 322.856 mg/L, and metarium anisopliae (CQMa421)205.921 cfu/mL, respectively. The highest and lowest LC50 for the 2nd instar nymphs of R. fuscipes were rotenone 139.596 mg/L and metartaria anisopliae(CQMa421)1 599.419 cfu/mL. The analysis of safety coefficient and benefit-to-harm toxicity ratio suggested that eucalyptol, metarhizium anisopliae, acetamiprid, pyrzidone, and metarhizium anisopliae(CQMa421)had good control effects on M. persicae, and had less toxicity on the 2nd instar nymphs of R. fuscipes. The plot experiments showed that the control effects of eucalyptol, pyrzidone, and metartaria anisopliae (CQMa421) combined with R. fuscipes were 93.14%, 91.22%, and 91.00%, respectively, which were better than using eucalyptol or R. fuscipes alone. [ABSTRACT FROM AUTHOR]