Study on the effect of normal hexane and Alcohol in plant extracts of Proboscidea fragrans, Nerium oleander, Datura innoxia and Hyoscyamus niger on Tetranychus urticae Koch ( Acari: Tetranychidae) in laboratory conditions

Two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is a polyphagous pest with high reproduction and adaptability rate. The application of chemical pesticides has made it resistant and some of these pesticides have actually become ineffective to this pest. Therefore, The main purpose of present study is the examination of these plant-based pesticides. In this study, the normal hexane and alcohol plant extracts of plants Proboscidea fragrans Decne, Nerium oleander Linnaeus,1753, Datura innoxia Miller, 1768 and Hyoscyamus niger Linnaeus,1265 have been examined. Extraction by drench and condensation with  rotary evaporator device and the Bioassay experiments were performed with the Leaf-Dip method. The results of this study showed that the LC50, extract of plant Proboscidea fragrans with Normal hexane (6500ppm) displays the highest effectivity and LC50, extract of plant Nerium oleander with Normal hexane (3500ppm) shows the lowest effectivity in 24 hour.
The plant extract Proboscidea fragrans  with normal hexane  and alcohol (80000 ppm) and the plant extract Proboscidea fragrans  with normal hexane (40000 ppm) with mean mertalaty of 100%  displayed the highest effectivity and the plant extract Datura innoxia with alcohol (20000 ppm) with mean mertalityal death of 14.03% showed the lowest effectivity. With regard to the present study and eco-friendlines and low risk of plant extracts, the extract Proboscidea fragrans  with normal hexane is a the best choice to be used to control Tetranychus urticae colonies in agricultural products. However, further studies are needed to apply this plant extract in IPM programs.