Efficiency of some Jasmonic Acid Concentrations on Mortality of Two-Spotted Spider Mite Tetranychus urticae Koch on Eggplant

Abstract

The efficiency of Jasmonic acid concentrations 0, 5, 50 and 100μM was examined mortality of adult female and nymphs of the two-spotted spider mite Tetranychus urticae fed on leaves of over four time intervals of 12, 24, 36 and 48 hours. The results showed the significant effect of the treatments on the corrected mortality ratios for both stages, as well as for the interaction of the treatments of variety, concentration and time. In general, the results indicated the increase of mortality with the increase of the time period. It was observed that the concentration of 100μM during the time periods and all varieties and the concentration of 50μM after the time periods 24, 36 and 48 hours on the Barcelona variety and the concentration of 5μM during the last two time periods on the Bowie variety had the highest corrected mortality ratio, which was 100%, while the lowest mortality ratio was 0% at the concentration 5μM with 12 hours after treatment on adult females fed on the leaves of Jawaher variety. Regarding the effect of treatment on nymphal stage, In general, the results of the triple interaction between treatments indicated that the concentration of 5 μM had a synergistic effect along with Bowie variety and at all time periods in obtaining of the highest mortality ratio of individuals of nymphal stage (100%) and with significant differences from the other treatment while the same concentration after 12 hours of treatment achieved lowest mortality ratio of the nymph fed on the leaves of the variety Jawaher which amounted 0%.