Potential Repellency and Toxicity of Hexane Extracts from <i>Cyperus rotundus</i> to <i>Tetranychus urticae</i> Koch. (Acari: Tetranychidae)

Abstract

The objective of this work was to evaluate the acaricidal and repellency effect of Cyperus rotundus extract, an important weed plant, on Tetranychus urticae adults. Randomized complete block with 4 replicates was adopted. The hexane C. rotundus extract was obtained from tubers using the Soxhlet apparatus, then diluted to 5 concentrations (C1-100%, C2-50%, C3-25%, C4-10% and C5-1%), and a control (distillate water). Results showed that five concentrations caused significant mortality of T. urticae adults 24, 48 and 72 hr after treatment. The higher mortality was observed with C1 concentration of C. rotundus extract 72 hr after treatment (97%). Three concentrations C1, C2 and C3 showed a repellent effect on T. urticae adults. The repellence index ranged from 25 to 55% for C3 and C1, respectively. The present study demonstrated that the C. rotundus extracts could be an effective acaricide on T. urticae adults since the LC50 obtained was 30.95%.