Screening For Aphidicidal Substances From Several Plant Extracts And Synergistic Study

Aphids are destructive pests in agricultural production, and the prevention and control of the aphids is difficult because of the appearent variety, high reproductivity and short generation time. For a long time, aphids have brought huge losses to flower plants, Lycium chinense Mill., and various crops in China. Recently, numbers of chemical pesticides have been used in the agriculture to kill aphids, which resulted in serious resistance to aphids, particularly brought great harm to human health with the use in flowers, fruit trees, tea and traditional Chinese medical plants. For botanical insecticides have low toxicity, safe, no residue and other characteristics, so discovering botanical agents from plants and develop highly effective eco-friendly and safe pesticides is an effective way to develop new pesticide. The study focused on screening high active substances from 150 kinds of botanical extracts, the synergism by mixed use as well as the preparation. The important results are as follows:1. According to the rezults of dipping insects and leaves trails, the 5 of Z1, turpentine,Z2,Z3, Kochia scoparia acetone extracts among 150 kinds of plants substances showed high activity against Myzus persicae and Aphis sp..2. The 5 kinds of selected active substances were combined and combined with traditional insecticidal plant material rotenone, nicotine. The rezults showed 4 of it, Z1 and nicotine, Z1and turpentine, Z2(acetone extract) and turpentine, Z3(acetone extract) and turpentine, had higher coordinate synergism, with the c.f of 74.13, 75.78, 30.42 and 27.67 respectively. Besides, the optimum ratios of Z1and nicotine, Z1 and turpentine were 1 to 5, 1.15 to 1, and the CTC values were 292.93 and 309.17.3. According to the results, by the study of screening test of environment-friendly solvents and surfactants, the eligible formulation of the two kinds of botanical aphicide 28% FJ-1 environment-friendly emulsion, 14% FJ-2 environment-friendly emulsion have been developed, and both of them reached pesticide products quality standards.4. Two kinds of formulas, 28% FJ-1 emulsion, 14% FJ-2 emulsion were tested in fields against aphis sp.. The datas indicated FJ-2 emulsion showed higher aphicidal activity, and the protection ratios were more than 90% in 500 times within 7days, no significant difference from 5% imidacloprid emulsion in 3000 times. Thus, FJ-2 emulsion have good application value.