Evaluation of Eruca Sativa and Capsicum annuum alcoholic extracts as pesticide against aphid and whitefly pests

Abstract

The aphid (Aphidoidea family) and the whitefly (Aleyrodidae family) are closely related, quickly breeding insects that, when infected, render plants susceptible to diseases since they suck the juices of these plants. They damage the aerial parts of plants and even their roots. Their control is of high concern to limit the damage and minimize the loss of the crops with the use of the safest pesticides. The present study was conducted to assess the perished effect of the Eruca sativa (local name: arugula) leaves and the Capsicum annuum (local name: hot pepper) fruits on aphids and on the eggs and nymphs of whitefly by spraying their alcoholic extracts on tested species. Three pesticide concentrations (0.5, 1 and 1.5%) of either extract were prepared and tested. Adhesives, propellants and other materials were added to the extracts to enhance their effectiveness. The results indicated that the pesticide prepared from these extracts has a concentration- and time-dependent impact on the growth of all tested species; the highest mortality rate was achieved at 1.5% concentrations. The time required for that highest effect was 72 hours for Eruca sativa leaf extract on aphids (100%); and on the eggs (89%) and nymphs (94.1%) of whiteflies. Meanwhile, the highest mortality rates achieved by 1.5% Capsicum annuum fruit extract were after 48 hours on aphids (100%), on the nymphs of whiteflies (100%), and 72 hours on whitefly eggs (96.4%). These effects may be related to the presence of many bioactive substances that were detected in the extracts of these two plants, including tannins, glycosides, phenols, resins, flavonoids, saponins, alkaloids, coumarin, steroids and terpenes.