ABSTRACT
Objective To investigate the molluscicidal effect of 5%niclosamide ethanolamine granules against Oncomela-nia hupensis in a marshland field. Methods The 5%niclosamide ethanolamine granules were sprayed at a dose of 40 g/m2 on 3 snail-breeding marshlands in Yangzhong City of Jiangsu Province to assess its field molluscicidal actions while 26%suspension concentrate of metaldehyde and niclosamide MNSC) at a dose of 4 g/m2 and fresh water served as controls. Results After seven days spraying, 5%niclosamide ethanolamine granules resulted in a of snail mortal85.42%ity while the mortality rates of snails were 82.35% and 2.86% in the MNSC and water control groups respectively. Conclusion 5% niclosamide ethanol-amine granules exhibit a high molluscicidal activity which is suitable to be used in the mashland.
ABSTRACT
In order to evaluate the moUuseicidal effect of 50% wettable power of niclosamide ethanolamine salt(WPN)combined with urea against Oncomelania snails in the field,4 g/m~2 WPN,4 g/m~2 WPN+20 g/m2 urea and 4 g/m~2 WPN+30 g/m~2 urea were used for mollusciciding with the spraying method.The results showed after 7 days,the mortality rates of snail were 74.43% for 4 g/m~2 WPN,90.32% for 4 g/m~2 WPN+20 g/m~2 urea and 94.83% for 4 g/m~2 WPN+30 g/m~2 urea,respectively.It is indicated that WPN combined with urea can improve the molluscieidal effect significantly.
ABSTRACT
Objective To evaluate the long-term molluscicidal effect of suspension concentrate of niclosamide (SCN) spraying in marshland regions of the Yangtze River. Methods A marshland with Oncomelania snails in Yangzhong City, Jiangsu Province, was selected as the study spot, and a dose of 6-8 g/m2 of SCN was sprayed yearly for four successive years, and the status of snails was investigated. Results From 2004 to 2007, the average densities of living snails were 6.00, 4.25, 2.04, 1.95 snails/0.1 m2, respectively before the use of molluscicide, and 0.86, 0.86, 0.23, 0.16 snails/0.1 m2, respectively after that. The average densities of living snails before and after the use of molluscicide reduced year by year, and the reduction rates of average densities of living snails were 85.67%, 79.76%, 88.49% and 91.78%, respectively from 2004 to 2007. The rate of frames with snails after the use of molluscicide was 73.46% in 2007, with a reduction rate of 86.85% compared with 9.66% of that before the use of molluscicide in 2004, and the average density of living snails reduced from 6.00 snails/0.1 m2 to 0.16 snails/0.1 m2, with a reduction rate of 97.33%. Conclusions After the spraying for four successive years, the density of snails reduces significantly and the molluscicidal effect is stable and reliable. SCN is a formulation of molluscicide for long-term application in marshland regions.