Study of the insecticidal effect of Oregano and Thyme essential oils and Neem carrier oil on the alfalfa aphid

Abstract

The insecticidal effect of some essential oils (Thyme and Oregano) and a vegetable oil (Neem) on aphids is presented in this work. With this purpose, dilutions and formulations of these oils were prepared and sprayed in plots of green alfalfa infested by aphid parasites.

The study of the mortality of aphids with time and dose of these natural extracts has pointed out their capacity to limit the growth of these parasites. Furthermore, these natural oils present the advantage of being more environmentally friendly and less hazardous for the human health than the conventional synthetic insecticides.

Among the natural oils tested the extracts of Oregano and the mixture prepared were the most effective in term of aphid mortality. Moreover, the mixture presented a remarkable synergy of its constituents which is an important feature of this treatment since these are usually used and found on the African continent.