Abstract: Liriomyza sativae Blanchard (Diptera: Agromyzidae) is one of the important pests harming a wide variety of vegetables and ornamental plants throughout the world. The leaf ethanol extract of Momordica charantia at the concentration of 2000〖KG-*2〗-〖KG-*7〗4000 μg·ml-1 displayed significant antifeedant and antioviposition activities against L. sativae adults. For further purifying the extract, four solvents, i.e., cyclohexane, ethyl acetate, n-butanol and water, were used to extract the ethanol extract, and the antifeedant and antioviposition activities of the extracts against L. sativae adults were te sted. The results showed that after treated with the extracts at the concentration of 1000 μg·ml-1 for 2 days, the antifeedant index (AFI) of cyclohexane-, ethyl acetate-, n-butanol- and water extracts against L. sativae adults was 1108%, 3489%, 2299% and 0, and the antioviposition index (AOI ) was 0, 3091%, 645% and 0, respectively. Ethyl acetate extract had the highest bioactivity. At the concentration of 4000 μg·ml-1, the AFI and AOI of ethyl acetate extract were 7095% and 6949%, respectively. The ethyl acetate extract was then isolated by silica gel column chromatography, a nd three compounds, i.e., (19S, 23E)-5β,19-epoxy-19-methoxy-cucurbita-6,23-dien-3β and 25-diol (compound 1), (19R, 23E)-5β,19-epoxy-19-methoxy-cucurbita-6,23-dien-3β and 25-diol (compound 2), and 3β,7β,25-trihydroxycucurbita-5,23-dien-19-al-3-O-β-D-glucopyranoside (compound 3), were obtained. These three compounds at concentration of 100〖KG-*2〗-〖KG-*7〗400 μg·ml-1 all had inhibitory effects on the feeding and oviposition of L. sativae. At the concentration of 400 μg·ml-1, the AFI and AOI were 6689%, 5353% and 7802%, and 7632%, 5836% and 7836% for compound 1, 2 and 3, respectively.

Key words: Phyllostachys edulis expansion, nitrogen mineralization, nitrogen availability, evergreen broadleaf forest, Dagangshan Mountain of Jiangxi Province.