Insecticidal Activity of Eupatorium fortunei Essential Oil Against Schizaphis graminum and Its Effects on...

Schizaphis graminum is the most important pest of wheat, and its feeding harm not only affects photosynthesis but also causes diseases, posing a serious threat to wheat production. We measured the contact killing and fumigation activities, population changes, enzyme activities, and nanoemulsion physicochemical property of Eupatorium fortune essential oil (EFEO) and pyrethrin against S. graminum and its natural enemy (Harmonia axyridis). Toxic effects of EFEO and pyrethrin increased with increasing concentration. After 24 h of contact killing, the LD₅₀ of S. graminum were 9.23 and 0.02 μg/head, respectively. Harmonia axyridis were 36.71 and 0.07 μg/head. The fumigation of EFEO LD₅₀ on S. graminum was 9.779 mg/L (y = 2.88x - 2.852). EFEO contains 28 chemical components, including l-Caryophyllene, Lily aldehyde, α-Terpineol, and Cineole. EFEO LD₅₀ significantly reduced the adult longevity, nymph production, and nymph production duration of the F0 S. graminum, while there were no significant differences in various parameters of offspring. The activity of acetylcholinesterase, glutathione-S-transferase, and carboxylesterase is significantly affected. The population decline rate of EFEO nanoemulsion is significantly higher than that of EFEO. This research aims to clarify the toxic effect of EFEO on S. graminum, providing a scientific basis for developing new plant essential oil preparations and nano preparations.