Assessment of toxicity on the basis of total phenolic content in oleander leaves (Nerium oleander L.) against Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae)

Abstract

Nerium oleander is an evergreen flowering shrub or small tree distributed widely in the Mediterranean region. It is also a source of polyphenols and cardenolides with insecticidal effect which could be a safe alternative of chemical control of insect pests. In the present work, five concentrations (0 %, 1 %, 2.5 %, 5 %, and 10 %) of ethanolic extract from Nerium oleander leaves were evaluated for its insecticidal effect against 3 to 4 days old Myzus persicae individuals under laboratory conditions. Obtained results showed a significant insecticidal effect with 70 % of mortality at the highest concentration (10 %). Total phenolic content of leaf ethanolic extract of this plant was 1721.36 mg gallic acid equivalent 100 g-1 dry matter. The results obtained suggest that we could make bioinsecticides based on leaves ethanolic extracts from N. oleander which rich in polyphenols for use eventually in integrated pest management.