title: [Molluscicidal effect of WPN and MNSC on Lymnaea].
abstract: OBJECTIVE
  To evaluate the molluscicidal effect of wettable powder of 50% niclosamide ethanolamide salt (WPN) and suspension concentrate of 26% metaldehyde and niclosamide (MNSC) on Lymnaea.
  
  
  METHODS
  WPN and MNSC were prepared as a series of solutions containing the active ingredient concentrations of 0.06, 0.13, 0.25, 0.50, 1.00, 2.00 mg/L and 4.00 mg/L, and the adult Lymnaea snails were soaked in the above mentioned series of solutions in the laboratory, and the LC50 values were calculated. The doses of active ingredient concentrations of 0.03, 0.06, 0.13, 0.25, 0.50, 1.00 g/m2 and 2.00 g/m2 of WPN and MNSC were adopted to spray on Lymnaea snails in the laboratory, and the LC50 values were calculated. A series of solutions containing the active ingredient concentrations of 1.00 mg/L, 0.50 mg/L, 0.25 mg/L, and 0.13 mg/L of WPN and MNSC were prepared, and the adult Lymnaea snails were put into the bowls with each concentration solution above mentioned and the climbing situation of the snails was observed at different time.
  
  
  RESULTS
  By the immersion method, LC50 values of WPN at 48 h and 72 h were 0.93 mg/L and 0.64 mg/L respectively; LC50 values of MNSC at 48 h and 72 h were 0.74 mg/L and 0.51 mg/L respectively; by the spray method, when active ingredient concentrations of WPN and MNSC were 1.00 g/m2 or more, the death rates were both 100% after 3 days. In the climbing test, the Lymnaea snails did not climb in the solutions containing the active ingredient concentration of 1.00 mg/L of WPN and MNSC, however, a few snails climbed in the low concentrations.
  
  
  CONCLUSIONS
  WPN and MNSC both have the effect of killing Lymnaea snails and inhibiting their climbing. By using the immersion method in the field, the active ingredient concentration of 2.00 mg/L of WPN and MNSC for 48 h is appropriate; by using the spray method, the active ingredient content of 1.00 g/m2 of WPN and MNSC for 3 days is appropriate.
authors.affiliation: Dali Prefecture Institute of Schistosomiasis Prevention and Control, Dali 671000, Yunnan Province, China.
authors.forename: Shang-Wei
authors.initials: SW
authors.lastname: Wang
authors.forename: Hai-Ying
authors.initials: HY
authors.lastname: Wang
authors.forename: Bing-Rong
authors.initials: BR
authors.lastname: Luo
authors.forename: Ke-Rong
authors.initials: KR
authors.lastname: Li
authors.forename: Yu-Hua
authors.initials: YH
authors.lastname: Liu
authors.forename: Shen-Hua
authors.initials: SH
authors.lastname: Zhao
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Tian-Mei
authors.initials: TM
authors.lastname: Li
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D008195:Lymnaea / Q000502:physiology; D008975:Molluscacides; D009068:Movement / Q000187:drug effects; D009534:Niclosamide; D011208:Powders; D013535:Suspensions; D013997:Time Factors
chemical_list: D008975:Molluscacides; D011208:Powders; D013535:Suspensions; C002935:metaldehyde; D009534:Niclosamide; D000079:Acetaldehyde