Chemical Analysis of Woodcreosote for Species-specific Attraction of Mosquito Oviposition (original) (raw)

Abstract

Since the attactive plant-phenolic compounds were postulated to occur in the mosquito-breeding field waters, the attractancy of woodcreosote for mosquito oviposition was investigated with 5 species mosquitoes in 6 colonies.The chemical analysis of creosote with a GC-Mass spectrograph revealed 20 homologus and analogus phenolic constituents.Eleven chromatographic fractions and 11 authentic compounds were bioassayed. Both 3, 5-xylenol and 2, 3-xylenol were quite attractive to the Denken colony of C. p. pallens individually and in the mixed fraction, but to Ar. subalbatus only the mixed fraction was so. 3, 5-Xylenol and its mixture with 2, 3-xylenol was also attractive to A. togoi. 2, 3-Xylenol and its mixture with 3, 5-xylenol was attractive to A. aegypti. 2, 6-Xylenol was also attractive to A.aegypti.The creosote included other compounds such as 2-methoxy-x-methylphenol attractive to the Denken colony of C. p. pallens, trimethylphenols attractive to C. p. molesuts, and 2-methoxy-x-methylphenol attractive to C. p. pallens, C. p. molestus and A. togoi. The alkyl moiety of these attractive compounds are presumably on 3- or 6-position of the benzene ring judging from the configurations of the above attractive dimethylphenols.Since the attractancy of natural material such as the creosote is derived either from single attractive constituent or oftener from combination of the attractive and closely related inactive compounds, the complete chemical analysis and the bioassay on every combinations of the related constituents are suggested to obtain the best formula for oviposition attraction.