Insecticidal activity of the crude extract from Epichloë bromicola against Rhopalosiphum padi

State Key Laboratory of Grassland Agro-ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, China

^* songqy@lzu.edu.cn

Abstract

Rhopalosiphum padi is a important pest in agricultural production. In order to reduce the use of chemical pesticides and improve the control effect, we reported the insecticidal activity of the crude extract from 20 strains Epichloë bromicola isolated from Elymus tangutorum. The results showed that the crude extract of E. bromicola had certain insecticidal activity against R. padi. The experimental results showed that 10 strains with good activity were 2, 3, 5, 7, 8, 11, 16, 18, 12 and 19, and their mortality rate reached more than 50% at 48h. However, the four strains of 13, 14, 15 and 17 had no insecticidal activity, but could promote the growth of R. padi. Among them, strain 7 had the best insecticidal activity at 48h, and the mortality rate reached 88.3%. The weakest insecticidal activity was strain 14, with a mortality rate of 21.7%. Strain 18 had the best insecticidal activity within 24h, with a mortality rate of 33.3%. At the same time, the mortality rate of 48h was significantly higher than that of 24h. In conclusion, these strains with significant insecticidal activity will be of great significance for the biological control of R. padi in the future.