Fumigant toxicity of Citrus sinensis essential oil on Musca domestica L. adults in the absence and presence of a P450 inhibitor

Essential oils (EOs) are potential tools for controlling Musca domestica L In a fumigant assay, M. domestica adults treated with Citrus sinensis EO (LC50=3.9 mg/dm(3)), with (4R)(+)-limonene (95.1%) being its main component, died within 15 min or less. The terpenes absorbed by the flies and their metabolites, analyzed using SPME fiber, were (4R)(+)-limonene (LC50=6.2 mg/dm(3)), alpha-pinene (LC50=11.5 mg/dm(3)), beta-Pinene (LC50=6.4 mg/dm(3)), and two new components, carveol (LC50=1122 mg/dm(3)) and carvone (LC50=19 mg/dm(3)), in a proportion of 50, 6.2, 12.5, 6.3 and 25%, respectively. Carveol and carvone were formed by oxidation of (4R)(+)-limonene mediated by cytochrome P450, as was suggested by a fumigation assay on flies previously treated with piperonyl butoxide, a P450 inhibitor. In this experiment, an increase in the toxicity of the EO and (4R)(+)-limonene was observed, as well as a lower production of carveol and carvone. (C) 2013 Elsevier B.V. All rights reserved.