Fumigate efficacy of Juniperus foetidissima essential oil and two terpenes against Phthorimaea operculella
Abstract
Introduction: Potato (Solanum tuberosum L.) is an important vegetable crop in Syria. Potato tuber moth
Phthorimaea operculella is the main damaging pest of this crop. Many approaches were tried to control it.
Objectives: This study evaluates the insecticidal activity of Juniperus foetidissima essential oil and two
monoterpenes against potato tuber moth using fumigation bioassays.
Methods: Essential oil was extracted from new plant branches of Juniperus foetidissima using Clevengertype
apparatus. Potato tuber moth Phthorimaea operculella, (adults, eggs, larvae, and pupae) were exposed
to different concentrations of the essential oil of Juniperus foetidissima for various periods. The significance
of differences between treatments at p<0.05 were evaluated by one-way analysis of variance using the mortality
percentages data. The LC50 and LC90 were calculated by Probit analysis.
Results: Essential oil vapor with LC50: 0.3 μl/l air was very effective against potato tuber moth at the adult
stage. However; adults sensitivity to monoterpenes varied: Nerol caused a 100% mortality at 0.025 μl/l air
after 6 h, while the same concentration of citronellol caused 98% mortality. The 0.125 μl/l air concentration
of the two compounds caused 100% mortality after 6 h.
Conclusion: Results suggest the possibility of using Juniperus foetidissima essential oil as a fumigant to control
potato tuber moth infestation in stores.