Abstract: Objective　To evaluate the molluscicidal effect of spraying 5% niclosamide ethanolamine salt granules with drones against of Oncomelania hupensis snails in snail habitats in marshland areas. Methods　From September to October, 2022, marshlands were sampled from Dantu District, Zhenjiang City, Jiangsu Province as study areas, and assigned into four groups, of approximately 3 000 m2 per group. In Group A, environmental cleaning was performed, followed by spraying 5% niclosamide ethanolamine salt granules with knapsack sprayers at a dose of 40 g/m2, and in Group B, 5% niclosamide ethanolamine salt granules were sprayed with knapsack sprayers at a dose of 40 g/m2 without environmental cleaning, while in Group C, environmental cleaning was conducted, followed by spraying 5% niclosamide ethanolamine salt granules with drones at a dose of 40 g/m2, and in Group D, 5% niclosamide ethanolamine salt granules were sprayed with drones at a dose of 40 g/m2 without environmental cleaning. Then, the study areas in each group were equally divided into six blocks, with Block 1 for baseline surveys and blocks 2 to 6 for snail surveys 1, 3, 5, 7, 14 days following chemical treatment. The mortality of snails and the reduction of the density of living snails were calculated. Results　A total of 132 frames were surveyed during the period from September to October 2022, and the occurrence of frames with living snails and means density of living snails were 61.36% (81/132) and 1.58 snails/0.1 m2, respectively. The overall mortality rates of snails were 43.02% (77/179), 38.69% (77/199), 47.78% (86/180) and 31.02% (58/187) 14 days following chemical treatment in groups A, B, C and D, respectively ([χ2] = 11.646, P < 0.05), and there were differences detected in the snail mortality between group A and D, and between groups C and D (both Padjusted values < 0.05). The adjusted mortality rates of snails were 37.42%, 36.07%, 38.85% and 40.40% in groups A, B, C and D 14 days post⁃treatment, and the density of living snails decreased by 48.10%, 63.29%, 67.09% and 69.62% 14 days post⁃treatment relative to pre⁃treatment, respectively. Conclusions　Chemical treatment with drones is feasible for O. hupensis snail control in marshland areas; however, the molluscicidal effect of spraying 5% niclosamide ethanolamine salt granules with drones is comparable to spraying chemicals manually in marshland areas regardless of environmental cleaning.

Key words: Oncomelania hupensis, Drone, 5% niclosamide ethanolamine salt granules, Marshland area, Molluscicidal effect

摘要： 目的　评价在江滩钉螺孳生环境中运用无人机喷撒5%杀螺胺乙醇胺盐颗粒剂的灭螺效果。方法　2022年9—10月，于江苏省镇江市丹徒区选取某块江滩为试验现场，将其分为A、B、C、D 4组，每组面积约3 000 m2。 A组清障后以背负式喷撒机施药，B组不清障以背负式喷撒机施药，C组清障后以无人机施药，D组不清障以无人机施药。各组灭螺药物均为5%杀螺胺乙醇胺盐颗粒剂，剂量为40 g/m2。将4组实验区域分别均分为6个地块，依次编号为1 ~ 6区，1区用于开展基线调查，2 ~ 6区分别用于施药后1、3、5、7 d和14 d开展钉螺调查。于施药前及施药后1、3、5、7 d和14 d开展钉螺调查，计算各组钉螺死亡率和活螺密度下降率。结果　施药前累计查螺132框，活螺框出现率为61.36%（81/132），活螺平均密度为1.58只/0.1 m2。施药后1 ~ 14 d，A、B、C、D组钉螺总死亡率分别为43.02%（77/179）、38.69%（77/199）、47.78%（86/180）和31.02%（58/187），差异有统计学意义（[χ2] = 11.646，P < 0.05），其中A、C组钉螺死亡率均高于D组，差异均有统计学意义（P校正均< 0.05）；各组钉螺校正死亡率分别为37.42%、36.07%、38.85%和40.40%；活螺密度分别较施药前下降了48.10%、63.29%、67.09%和69.62%。结论　在江滩环境可采用无人机开展药物灭螺；但无论环境是否清障，在江滩环境采用无人机喷撒5%杀螺胺乙醇胺盐颗粒剂的灭螺效果均与人工喷撒效果相近。

关键词: 钉螺, 无人机, 5%杀螺胺乙醇胺盐颗粒剂, 江滩, 灭螺效果