CHEMICAL-CONSTITUENTS OF ESSENTIAL OILS OF MUNA, BOLIVIAN PLANTS TRADITIONALLY USED AS PESTICIDES, AND THEIR INSECTICIDAL PROPERTIES AGAINST CHAGAS-DISEASE VECTORS

The composition of essential oils from two muna, Bolivian medicinal pl ants, derived from Minthostachys andina and Hedomea mandonianum, were analyzed by gas chromatography/mass spectrometry. Major differences we re observed in their chemical composition. Pulegone was the major comp onent of H. mandonianum oil (44.6%) and M. andina oil (25.5%); menthon e and isomenthone were around 33% of these oils. Differences were also observed in their insecticidal activity against the Chagas' disease v ector, Rhodnius neglectus or Triatoma infestans bugs exposed on impreg nated oil filter papers. While M. andina oil showed 30%-50% of mortali ty in both triatomine species after a period of 1 week, H. mandonianum oil did not show any insecticidal activity. Nevertheless, both specie s had insecticidal activity (33.3% and 50%) when oils were topically a pplied. The significance of these results is discussed in relation to the variability of the chemical composition and their potential use in Chasgas' disease vector control.