Insecticidal effect of the methanolic extract of Argemone mexicana for the control of Bactericera cockerelli (Sulc.) (Hemiptera: Triozidae)

Abstract

Argemone mexicana L. is a weed; used as a medicinal plant. The biological activity of this plant against pathogens such as viruses, fungi, bacteria, protozoa, and pests in the crop; such property is associated with compounds such as flavonoids, glycosides, terpenoids, phenolic compounds, and alkaloids present in this plant. The objective of the study was to evaluate the effect of methanolic extract of A. mexicana as an insecticide on Bactericera cockerelli. A total of 13 metabolites identified by Gas Chromatography coupled to Mass Spectrometry; revealed six with reported biological activity; the compound identified as a [1,3]Benzodioxolo[5,6-e][2]benzazecin-14(6H)-one,5,7,8,15-tetrahydro-3,4-dimethoxy-6-methyl- is the second most abundant and is a benzylisoquinoline alkaloid. Mortality observed at 48 h was 83.6 and 83.9 % dependent on the high doses of 20 and 30 mg/mL, while at 72 h, an increase in mortality up to 97.2 % at concentrations of 8-30 mg/mL occurred. The mean lethal concentration was 7.63 mg/mL and a CL₉₅ of 107.98 mg/mL. The analysis of the methanolic extract of A. mexicana leaves revealed that it can potentially cause mortality in B. cockerelli nymphs as a plant-derived insecticide.