4种剂型杀螺胺乙醇胺盐现场应用效果与成本分析

目的观察4种剂型杀螺胺乙醇胺盐在湖沼地区垸内环境的现场灭螺效果,并计算其单位面积的灭螺成本,为流行区制定灭螺药物使用计划提供科学依据。方法选择荆州市江陵县同区域内1条有螺大型排水渠和1条无水渠作为试验现场。将排水渠分为9段,1段设为空白对照组,仅观察钉螺自然死亡率;其余8段为观察组,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。无水沟渠分为4段,1段设为空白对照组,仅观察钉螺自然死亡率;其余3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、50%杀螺胺乙醇胺盐可湿性粉剂。施药前及施药后7、15 d均采用系统抽样法查螺,以观察灭螺药物效果。采用单位成本法,计算灭螺药单位面积(1 m~2)成本。结果在有水沟渠灭螺现场,4%杀螺胺乙醇胺盐粉剂50 g/m~2、5%杀螺胺乙醇胺盐颗粒剂40 g/m~2、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2 g/m~2与4 g/m~2,施药后7 d钉螺死亡率为79.52%~97.87%,施药后15 d钉螺死亡率为71.00%~96.30%,与灭螺前比较,差异均有统计学意义(P均0.01)。同一剂型悬浮剂、可湿性粉剂剂量2 g/m~2与4 g/m~2比较,施药后7 d,钉螺死亡率差异有统计学意义(P均0.05)。在无水沟渠灭螺现场,4%杀螺胺乙醇胺盐粉剂、5%杀螺胺乙醇胺盐颗粒剂、50%杀螺胺乙醇胺盐可湿性粉剂,施药后7 d钉螺死亡率为97.14%~100%,15 d为94.32%~100%,与灭螺前相比差异均有统计学意义(P均0.01)。上述灭螺药物每1 m~2的单位成本在0.280~0.416元之间。结论粉剂与颗粒剂适用于湖沼地区垸内无水或水位不稳定环境灭螺,悬浮剂与可湿性粉剂适用于有水环境灭螺。粉剂单位成本最低,但施药时粉雾飘移严重。

Effects and cost of four formulations of niclosamide ethanolamine salt in Oncomelania hupensis snail control in field

Objective To investigate the effects and cost of four formulations of niclosamide ethanolamine salt in Oncomelania hupensis snail control in the field in marshland and lake regions， so as to provide the evidence for drawing up the plan of molluscicide using in schistosomiasis endemic areas. Methods One drainage channel and one channel without water in the same area with snails in Jiangling County， Jingzhou City were selected as the research fields. The drainage channel was divided into 9 sections， except one section as a blank control group where the natural death rate of snails was observed only， and the remaining 8 sections were taken as the observation groups， where different dosages of 4% niclosamide ethanolamine salt powder， 5% niclosamide ethanolamine salt granules， 25% niclosamide ethanolamine salt suspending agent， 26% metaldehyde and niclosamide ethanolamine salt suspending agent， and 50% niclosamide ethanolamine salt wettable powder were used respectively. The channel without water were divided into 4 sections， except one section as a blank control group， the other 3 segments were taken as the observation groups， where 4% niclosamide ethanolamine salt powder， 5% niclosamide ethanolamine salt granules， and 50% niclosamide ethanolamine salt wettable powder were used respectively. Before and after spraying molluscicide for 7 days and 15 days， the system sampling method was used to observe the effects of snail control. Meanwhile， the unit cost method was used to calculate the costs of the different mulluscicide formulations abovementioned in unit area （1 m2）. Results In the field at the drainage channel， the snail mortality rates of the groups spraying 4% niclosamide ethanolamine salt powder （50 g/m2）， 5% niclosamide ethanolamine salt granules （40 g/m2）， 25% niclosamide ethanolamine suspending agent， 26% metaldehyde and niclosamide ethanolamine salt suspending agent， and 50% niclosamide ethanolamine salt wettable powder （2 g/m2 and 4 g/m2） for 7 days were 79.52%?97.87%， while the rates after spraying for 15 days were 71.00%?96.30%， and compared with those before spraying， the differences were statistically significant （all [P< 0.01]）. For the groups spraying with 2 g/m2 or 4 g/m2 suspending agent as well as wettable powder for 7 days， the snail mortality rates were significantly different （both [P<0.05]）. In the field at the channel without water， the snail mortality rates of the 3 observation groups after spraying molluscicide for 7 days were 97.14%-100%， while for 15 days were 94.32 %-100%， and compared with the rates before spraying， all the differences were statistically significant （all P < 0.01）. The unit costs per 1 m2 of the molluscicide abovementioned were ranged from 0.280 Yuan to 0.416 Yuan. Conclusions In marshland area inside embankment， the molluscicide formulations of the powder and granule are suitable for the environments without water or with instability water level， while the molluscicide formulations of the suspended agents and wettable powder are suitable for the water environment. Though the unit cost of powder is the lowest， the molluscicide in this formulation flies away seriously.