Assessment of fumigant activities of some plant essential oils against sand flies

The aim of this thesis was to evaluate the fumigant toxicity of essential oils obtained from aerial parts of two endemic Lamiaceae plants [Dorystoechas hastata Boiss. & Heldr. ex Bentham and Origanum minutiflorum O. Schwarz et. H. Davis], naturally found in the Antalya region, on Phlebotomus sand flies collected from Alanya province. Fumigant activity was evaluated by exposing the sand flies to essential oil vapors at different concentrations (10-100 μl/L). The essential oils used in this thesis were isolated by using hydrodistillation method. Chemical analyzes of these essential oils were carried out by Gas Chromatography-Mass Spectrometry (GC: MS). The major compounds found in D. hastata essential oil were 1,8-cineole, borneol, camphor, myrecene and β-pinene while the main constituents of O. minutiflorum essential oil are carvacrol only. The only common component of these two essential oils is borneol. A decrease in the KT50 (knock time) value is observed in D. hastata and O. minutiflorum essential oils in a concentration dependent manner. D. hastata essential oil KT50 value at 10 μl/L is 24,73 minutes and at 100 μl/L is 15.66 minutes. At 10 μL/L and 100 μL/L in the essential oil of O. minutiflorum, KT50 values are 32,86 and 14,09 min, respectively. When two the essential oils were compared on the basis of fumigant toxicity, D. hastata essential oil is more toxic at 10, 20, 50 and 100 μl/L concentrations. In addition, there isn't statistical difference between 10-100 μL/L when essential oils are approach individually. The O. minutiflorum essential oil showed 76.42%mortality at the lowest dose (10 μL/L) and 76.42%at the highest dose (100 μL/L), while the D. hastata mortality rates were 88.63%and 97,72%respectively. As a results D. hastata essential oil was the more toxic to adult sand flies than O. minutiflorum. In toxicity tests, LC50 values for essential oils of D. hastata and O. minutiflorum against sand flies were 0.45, and 0.47 μl/L respectively.