[Preliminary screening tests of molluscicidal effect of extracts from Eucalyptus leaves].

Objective: To investigate the molluscicidal effects of extracts from five Eucalyptus leaves collected from Guangdong Province, China.

Methods: According to the WHO recommended indoor immersed method, the molluscicidal effects of extracts from five Eucalyptus leaves with 250, 100, 10 mg/L of water extraction, alcohol precipitation and organic solvent extraction were investigated.

Results: The dose-effect relationship showed that all the mortality rates of Oncomelania hupensis reached 80% with the volatile oil from five Eucalyptus leaves immersed at the concentrations of 100 mg/L for 48 h, and the mortality rates were both 93.3% with the volatile oil from Corymbia citriodora and Eucalyptus urophylla leaves. The mortality rate was up to 95% with the chloroform extract, and the mortality rate reached 60% at the concentrations of 10 mg/L for 48 h.

Conclusion: The volatile oils from five Eucalyptus leaves and the chloroform extract in alcohol extraction from Eucalyptus urophylla leaves are better than other solvents.