Larvicidal activity of essential oils of five Apiaceae taxa and some of their main constituents against Culex quinquefasciatus

Apiaceae are aromatic herbs producing essential oils which are used on an industrial scale for various purposes.Notably, Apiaceae essential oils may replace synthetic insecticides keeping most of their efficacy and avoidingenvironmental pollution and human poisoning. In the present work, we explored the insecticidal potential of theessential oils from five Apiaceae taxa, namely Sison amomum, Echinophora spinosa, Heracleum sph ondylium subsp.sphondylium, Heracleum sphondylium sub sp. ternatum, and Trachyspemum ammi, as well as their major constituents(sabinene, p-cymene, terpinolene, myristicin, and thymol), against the filariasis vector Culex quinquefasciatus. For thepurpose, the essential oils were obtained by hydrodistillation and their composition was achieved by gaschromatography/mass spectrometry (GC/MS). Their acute toxicity on third instar larvae of C. quinquefasciatus wasdetermined. The two most active ess ential oils were those from T. ammi fruits and E. spinosa roots, showing LC50below 20 ll/l and LD90below 50 ll/l. These oils were dominated by the monoterpene phenol thymol and thephenylpropanoid myristicin, respectively, which showed the strongest larvicidal activity (LC50of 15.1 and 16.3 ll/l,respectively) among the pure compounds tested. These results showed that Apiaceae may be useful as source oflarvicidal compounds to be used for the development of cheap, effective and eco-fr iendly insecticidal formulations.