Abstract: The repellent activity of steam-distilled essential oil from Zanthoxlu m beecheyamum var. alatum fresh leaves against Culex pipens quinquefasciatus was evaluated according to the “Laboratory Efficacy Criterions of Public Hea lth Insecticides for Pesticide Registration-Repellent (GB/T 17322.10〖KG-*2〗-〖KG-*7〗1998)” w ith some modifications in test procedure, the fumigating insecticidal activity o f the essential oil to Cx. pipens quinquefasciatus adults was assessed by th e “Efficacy Test Methods of Public Health Insecticides for Pesticide Registrati on-Method of Laboratory Efficacy Test for Electric Mat (GB 139175〖KG-*2〗- 〖KG-*7〗1992)”, and the larvicidal and pupicidal activities of the essential o il against Cx. pipens quinquefasciatus were investigated by immersion method in laboratory. Besides, the chemical components of the essential oil were analy zed and determined by gas chromatography-mass spectrometry. At the dosage of 1. 5 mg·cm-2, the essential oil provided 100% protection against laboratory-rear ed female blood-starved individuals of Cx. pipens quinquefasciatus for （654±017） h. The 24 h LC50 value of the essential oil for Cx. pipens quinquefasciatus adults w as 6895 μg·cm-3 when the fumigating dosage was 11850 μg·cm-3, and the KT50 value of the essential oil for the adults was 646 min. The 24 h LC50 value of the essential oil for IV in star larvae was 119020 μg·ml-1. Seventeen compounds in the essential o il were identified, accounting for 974% of the total. This essential oil exh ibited high repellent activity and remarkable toxicity against Cx. pipens qu inquefasciatus.

Key words: land cover, landscape pattern, Poyang Lake region of China, environment management.