Objective: To observe the Oncomelania hupensis snail control effects of molluscicides with different formulations in the ditch with unstable water level in field of marshland and lake areas, so as to provide the evidence for formulating the prevention strategies.
Methods: A drainage channel with O. hupensis snails in Jiangling County, Jingzhou City were selected as the study field, then it was divided into 6 segments, except 1 segment was treated as the blank control group for observing the natural mortality rate of the snails, the other 5 segments were treated as observation groups, where 4% niclosamide ethanolamine salt powder, 5% niclosamide ethanolamine salt granule, 25% suspension concentrate of niclosamide ethanolamine salt, 26% suspension concentrate of metaldehyde and niclosamide ethanolamine salt, 50% niclosamide ethanolamine salt wettable powder were applied respectively. Before and after the mollusciciding, the snail surveys were carried out through the systematic sampling method, and the short- and long-term effects of snail control were observed, and the mortality rates of the snails on the slope above the water level and those below the water level were compared.
Results: When 7 d and 15 d after mullusciciding, the mortality rates of snails on the slope above the water level in each observation group were 79.52%-97.87% and 90.43%-96.30%, respectively, when compared with those before mollusciciding, all the differences were statistically significant (all P < 0.01). When 7 d after mullusciciding, the mortality rates of snails below the water level in each observation group were 17.11%-50.00%, which were all lower than those of the snails on the slope above the water level in the corresponding groups (all P ＜ 0.05); when 15 d after mullusciciding, the rates were 9.43%-95.24%, and those in 25% suspension concentrate of niclosamide ethanolamine salt, 26% suspension concentrate of metaldehyde and niclosamide ethanolamine salt, 50% niclosamide ethanolamine salt wettable powder groups were all lower than those of the snails on the slope above the water level in the corresponding groups (all P ＜ 0.01). Compared with the densities of living snails before mollusciciding, those 6 months after mollusciciding in each observation group decreased by 70.21%-78.98%.
Conclusions: The molluscicides in the formulation of powders and granule are suitable for both the snail environment with or without water, while those in the formulation of suspension agents and wettable powders are suitable only for environments with water.
［摘要］目的 观察不同剂型灭螺药在湖沼地区水位不稳定沟渠的现场灭螺效果, 为制定防治对策提供科学依据。方 法 选择荆州市江陵县一条有螺排水渠作为试验现场, 分为6段; 除一段为空白对照组, 仅观察钉螺自然死亡率外, 其余 5段作为观察组, 分别施用4%杀螺胺乙醇胺盐粉剂、5%杀螺胺乙醇胺盐颗粒剂、25%杀螺胺乙醇胺盐悬浮剂、26 %四聚· 杀螺胺乙醇胺盐悬浮剂、50%杀螺胺乙醇胺盐可湿性粉剂。施药 前后均采用系统抽样法查螺, 观察灭螺药物近期和远期 效果, 并比较水位线上坡面与水位线下沿边水体钉螺死亡率。结果各观察组水位线上坡面施药后7 d钉螺死亡率为 79.52%～97.87%, 施药后15 d为90.43%～96.30%, 与灭螺前比较, 差异均有统计学意义 (P 均＜0.01) 。各观察组水位线 下水体施药后7 d钉螺死亡率为17.11%～50.00%, 均低于各组水位线上坡面钉螺死亡率, 差异均有统计学意义 (P 均＜ 0.05); 施药后15 d, 钉螺死亡率为9.43%～95.24%, 25%杀螺胺乙醇胺盐悬浮剂、26% 四聚·杀螺胺乙醇胺盐悬浮剂、50% 杀螺胺乙醇胺盐可湿性粉剂组钉螺死亡率低于水位线上坡面, 差异均有统计学意义 (P 均＜0.01) 。与灭前比较, 灭螺后6 个月各观察组活螺平均密度下降率为70.21%～78.98%。结论 粉剂与颗粒剂适用于无水或有水环境灭螺, 悬浮剂与可 湿性粉剂适用于有水环境灭螺。.
Keywords: 25% suspension concentrate of niclosamide ethanolamine salt; 26% suspension concentrate of metaldehyde and niclosamide ethanolamine salt; 4% niclosamide ethanolamine salt powder; 5% niclosamide ethanolamine salt granule; 50% niclosamide ethanolamine salt wettable powder; Ditch; Marshland and lake region; Molluscicide; Mortality rate; Oncomelania hupensis snail.