REPELLENCY OF ESSENTIAL OILS EXTRACTED FROM PLANTS IN THAILAND AGAINST FOUR MOSQUITO VECTORS (DIPTERA: CULICIDAE) AND OVIPOSITION DETERRENT EFFECTS AGAINST AEDES AEGYPTI  (DIPTERA: CULICIDAE)

Apiwat Tawatsin 1,5
Preecha Asavadachanukorn 2
Usavadee Thavara 1
Prapai Wongsinkongman 3
Jaree Bansidhi 3
Thidarat Boonruad 3
Pranee Chavalittumrong 3
Noppamas Soonthornchareonnon 4
Narumon Komalamisra 5
Mir S Mulla 6


Affiliations :
      1 National Institute of Health, Department of Medical Sciences, Ministry of Public Health, Nonthaburi
      2 Department of Statistics, Faculty of Commerce and Accountancy, Chulalongkorn University, Bangkok
       3 Medicinal Plant Research Institute, Department of Medical Sciences, Ministry of Public Health, Nonthaburi
      4 Department of Pharmacognosy, Faculty of Pharmacy, Mahidol University, Bangkok
      5 Department of Medical Entomology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
      6 Department of Entomology, University of California, Riverside, California, USA

Source :
       Southeast Asian J Trop Med Public Health Vol 37 No.5 September 2006 : 915-931

Language :
       English

Abstract
       In this study we evaluated and reported repellent effects of essential oils from Thai plants against 4 mosquito vectors: Aedes aegypti, Ae. albopictus, Anopheles dirus  and Culex quinquefasciatus  under laboratory conditions using human volunteers. The essential oils were extracted from 18 plant species, belonging to 11 families, and the oils were then prepared as 10% solution in absolute ethanol with additives. Two chemical repellents, deet and IR3535, were also prepared in the same formulation as the essential oil repellents and tested for repellency as controls. The essential oils were also evaluated for oviposition deterrent effects against Ae. aegypti  under laboratory conditions. The results show night-biting mosquitoes (An. dirus  and Cx. quinquefasciatus ) and Ae. albopictus  were more sensitive to all the essential oils (repellency 4.5 - 8 hours) than was Ae. aegypti  (repellency 0.3 - 2.8 hours), whereas deet and IR3535 provided excellent repellency against all four mosquito species (repellency 6.7- 8 hours). All essential oils exhibited oviposition deterrent activity against Ae. aegypti  with various degrees of repellency ranging from 16.6 to 94.7%, whereas deet and IR3535 had no repellency. The present study demonstrates the potential for using essential oils as mosquito repellents and oviposition deterrents. These findings may lead to new and more effective strategies for protection from and control of mosquitoes.

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