[Field evaluation of a novel plant molluscicide "Luo-wei" against Oncomelania hupensis snails II molluscicidal effect in the field of lake areas in Hanchuan City, Hubei Province].
OBJECTIVE
To evaluate the effect of a novel plant molluscicide "Luo-wei" (Tea-seed distilled saponins, TDS) against Oncomelania hupensis in the field of lake areas in Hanchuan City, Hubei Province.


METHODS
Immersing experiment and spraying experiment were carried out in 5 ditches and a beach land respectively in Hanchuan City, Hubei Province to compare the molluscicidal effects among 4% TDS, 50% wettable powder of niclosamide ethanolamine salt (WPN), and 26% suspension concentrate of metaldehyde and niclosamide (MNSC) by different dosages and time. The chi2 test or Fish's exact test was used to examine the differences of snail death rates among them.


RESULTS
After 72 h of immersing experiment, the snail death rates in the 2.5 g/m3 TDS group, 3.0 g/m3 TDS group, 2.0 g/m3 WPN group and 2.0 g/m3 MNSC group were 99.33%, 100%, 100%, and 100%, respectively, and there was no significant difference among them (P > 0.05). By the end of 15 d after the spraying experiments, the snail death rates were 91.86% in the 2.0 g/m2 MNSC group, 90.26% in the 5.0 g/m2 TDS group, 87.45% in the 2 g/m2 WPN group, and 86.10% in the 3 g/m2 TDS group. The differences between the 5.0 g/m2 TDS group and 2.0 g/m2 MNSC group, as well as the 3.0 g/m2 TDS group and the 2.0 g/m2 WPN group had no statistical significance (both P > 0.05).


CONCLUSIONS
The molluscicidal effect of TDS is similar to that of WPN or MNSC. The recommended dosage of TDS is 2.5 g/m3 for immersing or 5 g/ m2 for spraying in the field.
Hanchuan Institute of Schistosomiasis Prevention and Control, Hubei Province, Hanchuan 431600, China.
Zhi-hai
ZH
Zhang
Hanchuan Institute of Schistosomiasis Prevention and Control, Hubei Province, Hanchuan 431600, China.
Rong
R
Fang
Hanchuan Institute of Schistosomiasis Prevention and Control, Hubei Province, Hanchuan 431600, China.
Bin
B
Yu
Hanchuan Institute of Schistosomiasis Prevention and Control, Hubei Province, Hanchuan 431600, China.
Zhi-shuang
ZS
Liu
Hanchuan Institute of Schistosomiasis Prevention and Control, Hubei Province, Hanchuan 431600, China.
Ze-jun
ZJ
Zhao
Hanchuan Institute of Schistosomiasis Prevention and Control, Hubei Province, Hanchuan 431600, China.
Xin-wen
XW
Xu
Hanchuan Institute of Schistosomiasis Prevention and Control, Hubei Province, Hanchuan 431600, China.
Xiu-long
XL
Huang
National Institute of Parasitic Diseases, Chinese Centre for Disease Control and Prevention, WHO Collaborating Centre for Malaria, Schistosomiasis and Filariasis, China.
Tie-wu
TW
Jia
D000079:Acetaldehyde / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002681:China; D019856:Ethanolamine / Q000494:pharmacology; D060106:Lakes; D008975:Molluscacides / Q000494:pharmacology*; D009534:Niclosamide / Q000494:pharmacology; D012503:Saponins / Q000494:pharmacology*; D012908:Snails / Q000187:drug effects*
D008975:Molluscacides; D012503:Saponins; C002935:metaldehyde; D019856:Ethanolamine; D009534:Niclosamide; D000079:Acetaldehyde