Fumigant Toxicitiy of Essential Oils from Thymus argaeus Boissier & Balansa and Thymus sipyleus Boissier(Lamiaceae) Againts Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

Abstract

In the present study, insecticidal activity of essential oils of Thymus argaeus Boissier & Balansa and Thymus sipyleus Boissier were evaluated by fumigation method against different developmental stages of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). Essential oils were isolated by Clevenger apparatus. Both essential oils were highly effective against egg and adult stages of pest. On the other hand larvae of E. kuehniella were more resistant than other stages. The mortality values reached 100% when the adults were exposed to 5 and 1,5 μl/L air concentrations of T. argaeus and T. sipyleus essential oil, respectively. In all stages, T. sipyleus essential oil was found to be more effective than T. argaeus essential oil. Results showed that these essential oils have potential as fumigants against E. kuehniella under storage conditions.

Keywords: Thymus argaeus, Thymus sipyleus, Ephestia kuehniella, essential oil, insecticidal activity.