Phytochemical analyses and toxicity of Nerium oleander (Apocynaceae) leaf extracts against Chaitophorus leucomelas Koch, 1854 (Homoptera: Aphididae)
2022
Zaid, Ratiba | Canela-Garayoa, Ramon | Ortega-Chacón, Nancy Milena | Mouhouche, Fazia
In recent decades, phytochemicals in plant extracts have been recognized as having insecticidal activity against insect pests. They have also been described as an alternative method to synthetic chemicals. The present study is a contribution on the insecticidal activity, under semi-natural conditions, of extracts of Nerium oleander L. on viviparous females of Chaitophorus leucomelas. Two extraction methods were performed with polar solvent to obtain two extracts used to carry out the insecticide tests. To identify the highest number of metabolites present in the plant three approaches were performed using supercritical fluid, ultrasound and enzymatic methods. Thirty-eight bioactive molecules were identified by GC/MS, some of which could be responsible for the insecticidal activity on viviparous females of C. leucomelas. The enzymatic extraction showed a very high monoterpene content of 34.62%, while the supercritical fluid extraction gave a content of 71.91% of oxygenated terpenic compounds. The results relating to the temporal estimation of insecticidal activity of the three studied concentrations of pure methanol and methanol-water extracts were found to be effective in terms of toxicity to viviparous females of C. leucomelas. A 100% mortality rate was observed 4 days after treatment at a concentration of 5.15 g/m².
显示更多 [+] 显示较少 [-]