Investigation of toxicity and deterrent of oviposition of 3 essential oils on tomato fruit-worm Helicoverpa armigera (Hünber) (Lep., Noctidae)

The effects of essential oils of Eucalyptus salmonophloia, Rosmarinus officinalis and Momordica charantia on mortality of larvae and oviposition deterrence were investigated. For each essential oil, five concentrations (20, 120, 240, 3 60 and 480 ppm) were tested. The effect of essential oils on the mortality of larvae and ovipo sition deterrence increased with increasing the concentration of essential oils. The essential oils of M. charantia, R. officinalis and E. salmonophila in the maximum concentration (480 ppm) caused 100, 91 and 86 percent mortality of larvae of tomato fruit-worm, respectively. This ess ential oils reduced the oviposition rate of pests significantly. The essential oils of M. charantia ,R. officinalis and E. salmonophila in the highest concentration (480 ppm) caused the oviposition dete rrence of 86, 81 and 61 percent respectively. The value of calculated LC50 indicated that essenti al oil of M. charantia was more effective Than the other two essences.