Phytochemical characterization and bioactivity of ethanolic extracts on eggs of citrus blackfly

Abstract

The main objectives of this study were to determine the content of secondary metabolites (carotenoids, flavonoids, phenolic compounds, and tannins) of Argemone mexicana L., Ipomoea carnea Jacq. subsp. Fistulosa (Martius ex Choisy), Amorimia rigida (A.Juss.) W. R. Anderson, Ricinus communis L. and Syzygium aromaticum (L.) Merr. & L. M. Perry using UV-VIS spectroscopy, and evaluating the bioactivity of the ethanolic extracts on citrus blackfly eggs (Aleurocanthus woglumi Ashby, 1915). Pera sweet orange leaves infested with citrus blackfly eggs were treated by immersion in 0.5, 1.0, 5.0, and 10%; each replicate consisted of 30 eggs. The experimental design was completely randomized, with seven treatments and four replications. Three immersions of leaves with eggs were performed, and the mortality was evaluated seven days after the procedure. Leaves were placed in Petri dishes and kept in incubators [25±1°C; relative humidity (RH) 60±5% and 12 hours]. S. aromaticum peduncle presented high content of tannins and phenolic compounds, while R. communis leaves showed high content of phenolic compounds. The commercial product Bioneem© caused egg infeasibility greater than 85% at all concentrations. Treatments (10%) that caused the greatest egg mortality were Bioneem© (94.74%), R. communis extract (81.58%), and the extract of S. aromaticum peduncle (80.57%).