Toxic effect of three medicinal plant extracts on Myzus persicae (Sulzer) (Hem.: Aphididae)

The peach potato aphid Myzus persicae (Sulzer) (Hem.: Aphididae) is one of the most noxious species [1]. It can infest plants of over 40 different families including many economically important ones world wide, and it is able to transmit over 100 plant viruses [2]. Therefore, in the present study the efficacy of acetonic leaf extracts from three medicinal plants were evaluated against 3–4-day-old individuals of the M. persicae. The plants were included Eucalyptus globulus Labill. (Myrtaceae), Teucrium polium L. (lamiaceae) and Otostegia persica Boiss. (Labiatae). In order to obtain the crude extracts, the dried leaves were powdered and extracted with acetone. Experiments were carried out at 25±1°C temperature, relative humidity of 60±10% and 16 hours of artificial light at an intensity of about 4000 lux. In control treatments only distilled water and DMSO (dimethyl sulfoxide) were applied. Topical treated aphids with three acetonic extract emulsion (in distilled water with DMSO) were placed on the broad bean leaf discs (4.5cm diameter) in the round plastic Petri dishes (5.5cm diameter), filled with a 0.5-cm-thick agar gel layer. The highest percentage of mortality (55.6%) was observed in the acetonic leaf extract of O. persica in the concentration of 80µl/ml after 48 hours. While, it was less than 10% in the acetonic leaf extract of E. globulus. The acetonic leaf extract of T. polium caused 14.5% mortality of M. persicae. It is concluded that O. persica is the most promising for future development and use as botanical pesticide.

Keywords: Myzus persicae, medicinal plant, Toxic effect, Topical test

References: 1. Blackman RL, Eastop VF (1984) Aphids on the World's Crops. John Wiley and Sons. New York.

2. Clements KM et al. (2000) RevToxicol 3: 1–23.