Ali Abeedo*^{(1) (2)}, Mohamad Kanouh⁽²⁾, and Haifa Alsayeda⁽²⁾  

(1)  Pesticide Test Research Department, Plant Protection Research Department, General Commission for Scientific Agricultural Research, Damascus University, Damascus, Syria.  

(2) Department of Plant Protection, Faculty of Agriculture, Damascus University, Damascus, Syria.

(*Corresponding author: Ali Abeedo:  Email:aliabeedo265@gmail.com)

Received:7/07/2021            Accepted: 19/10/2021

Abstract: 

The present study was conducted at plant protection department laboratories (Faculty of Agriculture, University of Damascus) during 2020. This work aimed to estimate the effect of two chemical acaricides, Chlorpyrifos and Spiromesifen, and the effect of plant extracts of Melia azedarach L. and Eucalyptus camaldulensis Dehn against the eggs and adults of strawberry spider mite, Tetranychus turkestani under laboratory conditions. The relative efficiency and LC₅₀ of tested acaricides and plant extracts had been determined. The results showed significant differences in the adult mites’ mortality after the exposure to residues of acaricides and plant extracts between the control and the treatments. There were no significant differences between the two acaricides despite of the difference between their mode of action. According to LC₅₀ value, the toxicity of Spiromesifen to adult mites was 9.3 times higher than Chlorpyrifos, the toxicity of M. azedarach extract was 1.55 times higher than E. camaldulensis extract. Egg mortality rate had been determined after direct spray by tested acaricides and plant extracts. There were significant differences between the control and the treatments.

Keywords: Strawberry spider mite, Chlorpyrifos, Spiromesifen, Plant extracts, Melia azedarach, Eucalyptus camaldulensis, Relative efficiency, Toxicity index.

Full paper in Arabic: pdf