关键词: 氯代水杨胺； 钉螺； 血吸虫病； 灭螺效果； 效果评价

Abstract:

Objective Objective To evaluate the effects of a novel molluscicide，the salt quinoid?2′，5?dichloro?4′?nitrosalicylanilide from niclosamide（LDS），with 10% wettable powder，in main schistosomiasis epidemic areas of China，including Hunan、 Ji? angxi、 Hubei、 Anhui、 Jiangsu、 Sichuan、 Yunnan and Zhejiang provinces. Methods Methods In the immersion test，6 effective concentra? tions of 10% LDS were tested respectively：0.1，0.2，0.4，0.6，0.8 and 1.0 g/m3 in the field；at the same time，50% wettable powder of niclosamide ethanolamine salt（WPN）with effective concentrations of 1.0 g/m3 was used as the molluscicide control， and the fresh water as the blank control，then the mortality rates of O. hupensis snails were recorded at 24 h，48 h and 72 h after the immersion. In the spraying test and powder ? spraying test，5 effective dosages of 10% LDS were tested respectively：0.2，0.4，0.6，0.8 and 1.0 g/m2 ，while 50% WPN 1.0 g/m2 was used as the molluscicide control，and the fresh water as the blank con? trol in the field for 1 d，3 d and 7 d，then the mortality rates of O. hupensis snails were recorded at 1 d，3 d and 7 d after the spraying and powder?spraying. Results Results The snail mortality rates of LDS using the immersion test for 72 h were more than 95% in the field of eight provinces（0.1 g/m3 in Sichuan，Jiangxi，Jiangsu and Zhejiang provinces，0.2 g/m3 in Yunnan，Hunan and Hubei provinces，and 0.4 g/m3 in Anhui Province）；the snail mortality rates of LDS using the spraying test for 7 d were more than 85%（0.2 g/m2 in Hunan，Hubei，Jiangxi and Zhejiang provinces，0.4 g/m2 in Sichuan and Anhui provinces，0.6 g/m2 in Yunnan and Jiangsu provinces） . The snail mortality rates of LDS in the powder?spraying test for 7 d were more than 85%（0.6 g/ m2 in Yunnan，Sichuan，Hubei，Jiangxi，Anhui，Jiangsu and Zhejiang provinces） . According to the standards of“Efficacy test methods and evaluation of molluscicide for pesticide registration（NY/T 1617?2008） ” ，LDS is a qualified molluscicide. Conclu Conclu? ? sions sions LDS has good molluscicidal effects through the immersion，spraying and powder?spraying test in the fields. It is suitable for a variety of environments to control O. hupensis snails of schistosomiasis endemic areas in China. The recommended dosages of LDS are 0.1?0.2 g/m3 by the immersion method，0.2?0.4 g/m2 by the spraying method，and 0.4?0.6 g/m2 by the powder?spray? ing method in the fields.

Key words: Chlorosalicylicamide； Oncomelania hupensis； Schistosomiasis； Molluscicidal effect； Effect evaluation