Relationship between the yield of essential oil of different species of Eucalyptus, their percentage of 1,8 cineole and its larvicidal effect on Aedes aegypti (Diptera: culicidae).

ALEJANDRO LUCIA; HÉCTOR MASUH; SUSANA LICASTRO; EDUARDO ZERBA

Orlando Florida (USA)

Congreso; 73nd Annual Meeting of the American Mosquito Control Association – 17th Latinamerican Symposium; 2007

American Mosquito Control Association

In the search for new control tools against Ae.aegypti, larvicidal effect of essential oils from 12 species of Eucalyptus (myrtaceae) ( E. saligna Smith, E. cinerea F.v. Muell. ex Benth, E. dunnii Maiden, E. gunnii Hook. F, E. globulus ssp. maidenii F. v Muell, E. globulus ssp. globulus Labill, E. sideroxylon A. Cunn, E. viminalis Labill, Eucalyptus tereticornis Smith., Eucalyptus camaldulensis Dehnh. And two clonal hybrids Eucalyptus grandis x Eucalyptus tereticornis and Eucalyptus grandis x Eucalyptus camaldulensis) were evaluated. Essential oils were obtained by hydrodistillation of vegetal material collected in an experimental plot of our Centre in Buenos Aires, Argentina (S34 33.223, W58 30.523). To establish the larvicidal effect, the esential oils in acetonic solutions were added to 250 ml water containing 20 third or early fourth stage Ae.aegypti susceptible CIPEIN strain larvae. Mortality was determined after 24 hours. The yields of leaf essential oil were expressed as % w/w of essential oil weight by 100 gr of fresh plant material. The chemical composition of Eucalyptus essential oils were determined by gas chromatography coupled to mass spectrometry. Regression analysis revealed a statistically significant relationship between percentage of 1,8-cineole and yield of Eucalyptus essential oils. Additionally, regression analysis showed a relationship between percentage of 1,8-cineole and larval mortality. The results show that those species of Eucalyptus that have high values in yield of essential oil have in their chemical composition high content of 1,8 - cineole and additionally, this type of essential oil show low larvicide effect against Ae. aegypti. Results in work suggest that when the essential oil of Eucalyptus gets rich in 1,8 - cineole diminishes its larvicide effect on Aedes aegypti.