Determination of fumigant toxicity of single, binary and tertiary mixtures of three essential oils against Frankliniella occidentalis Pergande (Thysanoptera: Thripidae)

Abstract

Abstract In this study, three essential oils extracted from sage (Salvia officinalis L.), thyme (Thymus vulgaris L.) and daphne (Laurus nobilis L.) were used against the adult Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) pest, one by one and more Then, fumigant toxicity of binary (1:1) and tertiary (1:1:1) mixtures was investigated under laboratory conditions. The results showed that all essential oils tested, both alone and in all binary and tertiary mixtures, had fumigant toxicity on adult F. occidentalis. Mortality rates of 3–5 day old adults of F. occidentalis increased with increasing concentration from 20 to 100 µL/L. In the entire study, binary and tertiary mixtures of the oils were more successful than the individual application. At a dose of 10 µL/L, all binary and tertiary mixtures of the oils caused 100% mortality at all exposure time periods. However, in the application where sage oil was fumigated for 24 hours and applied alone, the mortality rate remained below 100%. The highest synergistic effect was found in triple essential oil mixtures (sage + daphne + thyme) with 1.0 µL/L air LC50 value in all application doses, counted after 48 hours. Our overall results show that binary and tertiary mixture of all tested essential oils are promising candidates for protection against western flower thrips.