Bioactivity of Annona montana Macfad extracts on the black cowpea aphid (Aphis craccivora Koch)

Abstract

This study aimed to verify the insecticidal activity and determine the LC50 of hydroethanolic extracts from Annona montana leaves and seeds on the black aphid, Aphis craccivora. The experiment was conducted in a greenhouse. Annona montana leaf and seed extracts were obtained by solvent extraction using 70% ethanol. The following spray treatments were applied on the black aphid nymphs: Hydroethanol (HE) extracts from leaves at concentrations of 2.5; 5; 10; 15%, and EH extracts from seeds at 0.5; 1.0; 1.5; 2%; Neemax® and distilled water (control). Results showed the presence of insecticidal effect of both extracts on A. craccivora nymphs. The HE from leaves was more efficient at the concentration of 15%, with 78% mortality of nymphs. In the case of HE from seeds, the largest mortality was obtained at the concentration of 2%. The acute toxicity of A. montana extracts on A. craccivora nymphs was 7.69 for HE from leaves and 0.55 for HE from seeds. Therefore both extracts of A. montana may be indicated to the control of the agricultural pest (A. craccivora).