Synergistic effects of essential oil-based cream formulations against Culex quinquefasciatus Say and Aedes aegypti L. (Diptera: Culicidae)

Mosquitoes are major arthropod vectors responsible for several pathogenic diseases. In recent years, repellents of botanical origin, particularly essential oils, have been used against mosquitoes and have been found effective and safe. In this study, five different repellent cream formulations (CF1-5) were prepared using combinations of essential oils, including camphor, cinnamon, citronella, lemongrass, lime, orange, neem, basil, Vitex, Lantana, eucalyptus, and clove, and their repellency was tested using Culex quinquefasciatus Say and Aedes aegypti L. under laboratory conditions and compared to the standard synthetic repellent N,N-diethyl-meta-toluamide (DEET-12%, w/w). Among the five cream formulations, CF2 at a dose of 5 mg/cm(2) showed the longest protection time of 4.18 h and 3.31 h against C quinquefasciatus and A. aegypti, respectively, under laboratory conditions. CF3 at a dose of 5 mg/cm(2) was moderately effective, with protection times of 3.42 h and 2.58 h against C. quinquefasciatus and A. aegypti, respectively, under laboratory conditions. CF2 at a dose of 5 mg/cm(2) was also tested in the field against wild mosquitoes for 3 h, and 100% protection was observed for the entire study period. Thus, CF2 could be used in developing an effective natural repellent as an alternative to the existing synthetic repellents to C quinquefasciatus and A. aegypti. (C) 2014 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society. Published by Elsevier B.V. All rights reserved.