Comparative effect of Thymus kotschyanus and Mentha longifolia essential oils on oviposition deterrence and repellency of Callosobruchus maculates F.

Cowpea weevil Callosobruchus maculatus (F.) is one of the serious post-harvest pests of stored products. The damaged seeds are unsuitable for human or animal consumption and also for farm cultivation. To control this pest in warehouses, usage of essential oils is considered as an appropriate alternative to synthetic pesticides. Therefore, a study was conducted to investigate oviposition deterrence and repellency effects of Thymus kotschyanus Boiss & Hohen and Mentha longifolia L. on C. maculatus. These plants were collected from around of Tehran. Essential oils were subjected to hydrodistillation using a Clevenger-type apparatus for 3 h. The experiments were done under dark condition in 27 ± 1 ˚C and 65 ± 5 % R.H. Essential oils significantly reduced oviposition of the adults as 500 µl of T. kotschyanus and M. longifolia essential oils (1800 ppm) caused 87.64 and 86.36% oviposition deterrence respectively. Also, essential oils had repellent activity on C. maculatus. At 800 ppm, repellency of M. longifolia and Thymus kotschyanus was recorded 90% and 73.33 % respectively.