Study on the Insecticidal Activities to Myzus Persicae of Extracts from Twenty Plant Species

In order to screen plant resource with significant insecticidal activities against M. Persicae, the effects of laboratory bioassays of 20 plant extracts to M. persicae were investigated by the immerse leaf method. The results showed that when the concentration was 48.83 mg/L, the 24 h corrected mortality of the extracts from Equisetum ramosissimum, Dicranostigma leptopodum and Ailanthus altissima were 53.33%, 56.67% and 74.67% respectively. It was found that 20 plant extracts exhibited various levels of insecticidal activities against M. Persicae. The pesticidal activities of A. altissima, D. leptopodum, E. ramosissimum, and D.stramonium were significantly higher than that of other tested extracts and the LC₅₀ were 26.618, 29.179, 41.484, and 87.741 mg/L, respectively. The results provide theoretical basis for biological control of M. persicae and scientific utilization of these 20 plant resources.