Study on the Acaricidal Effects of ‎Karala (Momordica charantia) ‎Fruit Extract Against Tetranychus ‎urticae (Acari: Tetranychidae)‎

Two-spotted spider mite, Tetranychus urticae (Acari:Tetranychidae), is one of the most important pests in plants, especially crops that it has high reproduction and ability to develop resistance to chemical pesticides. Considering the increasing of environmental pollution due to chemical pesticides, the use of plant extracts has received much attention as an alternative method due to their acaricidal activity. Therefore, this experiment was performed to determine the chemical compounds of Momordica charantia fruit extract and toxicity of hexane and ethanolic extracts of this plant on adults of two-spotted spider mite in a completely randomized design with the control in four replications for fumigant and contact toxicities and repellent activity. After 24 hours, the mortality of mites was recorded. The results of bioassays showed that the mortality rate of mites and the repellent effect elevated with increasing the concentration of M. charantia extracts. The hexane extract of M. charantia at the concentration of 1000 μg/cm2 had the highest mortality (75.56%) in contact toxicity. Ethanolic extract at the concentration of 1000 μl/l air had the highest mortality (79.89%) of mite in fumigant toxicity. The repellent effect increased to 80%, 5 hours after application of ethanolic extract by increasing the concentration from 200 μl. In M. charantia fruit extract, sixteen different compounds were identified in which monoterpenoids, linalool oxide, limonene oxide, and 8-hydroxilinalool, had the highest amount. Therefore, the ethanolic extract of M. charantia in high concentrations can be recommended due to its monoterpenoids to protect plants, especially crops, against two-spotted spider mite.