Oviposition deterrency of Thymus daenensis and Thymus carmanicus essential oils against Callosobruchus maculatus

Use of many chemical insecticides has been limited because of their toxicity to human, andenvironmental concerns, as well as exhibition of resistance problems in insects. Botanical insecticidescomposed of essential oils may be an alternative to the more persistent synthetic insecticides. In this study,oviposition deterrency (OD) of essential oils of Thymus daenensis Celak. and Thymus carmanicus Jalas. wastested on Callosobruchus maculatus (F.) at 27±1 ºC and 65±5% R.H. in dark condition. The essential oilswere obtained from dry leaves of T. daenensis and T. carmanicus and subjected to hydrodistillation using amodified clevenger-type apparatus. For each essential oil, six concentrations (0.04-0.24 μl/g seed) in fivereplications were used. In each vial, two pairs of adult insects were introduced to 5 g mung bean seeds.Findings showed that OD of T. daenensis was significantly higher than that of T. carmanicus. At the highestconcentration (0.24 μl/g seed), of T. daenensis and T. carmanicus, OD was reached to 95.73% and 92.51%respectively. At the lowest concentration (0.04 μl/g seed), of the above essential oils it was recorded to be12.86% and 5.16% respectively. Consequently, the essential oils of these plants sublethal concentrations hadconsiderable deterrency on C. maculatus.

کلیدواژه ها:

Thymus daenensis ، Thymus carmanicus ، Callosobruchus maculatus ، Oviposition deterrency