Abstract: Objective　To evaluate the molluscicidal effects and costs of spraying 20% suspension concentrate of pyriclobenzuron sulphate (SCPS) with drones against Pomacea canaliculata in paddy environments, so as to provide insights into the extensive applications of pyriclobenzuron against P. canaliculata. Methods　On July 2022, a paddy field was selected from Nanchang City, Jiangxi Province as the study area, and 72 independent rectangular plots measuring 2 m × 1 m were allocated in the study area, with 1 m interval between each plot, and 20 P. canaliculata snails gently placed in each plot. The activity of 25% wettable powder of pyriclobenzuron sulphate (WPPS) by manual spraying at doses of 0.50, 1.00, 2.00 g/m2 and 4.00 g/m2 against P. canaliculata was tested in 54 plots, and manual spraying of 50% wettable powder of niclosamide ethanolamine salt (WPNES) at a dose of 0.10 g/m2 served as a chemical control, while manual spraying of the same volume of clean water served as a blank control, with 9 plots in each group. The activity of SCPS against P. canaliculata was tested in the remaining 18 plots. Based on the molluscicidal tests of WPPS, the molluscicidal effect of SCPS by manual spraying at doses of 0.20, 0.30, 0.40 g/m2 and 0.50 g/m2 against P. canaliculata was evaluated, and manual spraying of WPNES at a dose of 0.10 g/m2 served as a chemical control, while manual spraying of the same volume of clean water served as a blank control, with three plots in each group. On July 2023, 14 paddy fields with a mean living P. canaliculata density of > 5 snails/m2 were selected from Yujiang District, Yingtan City, Jiangxi Province for molluscicidal tests. Based on the molluscicidal effect of pyriclobenzuron against P. canaliculata in plots, the molluscicidal effects of WPPS by manual spraying at doses of 0.25, 0.50 g/m2 and 1.00 g/m2 and manual applications of WPPS at dose of 0.25, 0.50, 1.00 g/m2 and 2.00 g/m2 mixed with soil were tested, and manual spraying of 0.10 g/m2 WPNES served as a chemical control group, while manual spraying of the same volume of clean water served as a blank control, with one paddy field in each group. Based on the effect of pyriclobenzuron against P. canaliculata in plots, the activity of SCPS sprayed with drones at doses of 0.25 g/m2 and 0.50 g/m2 mixed in water at 2 kg/667 m2 and 4 kg/667 m2 was tested against P. canaliculata, and spraying of the same volume of clean water with drones served as a blank control. All P. canaliculata snails were captured 3 days and 7 days following chemical treatment in plots and paddy fields and identified for survival, and the mortality and corrected mortality of P. canaliculata snails were estimated. In addition, the areas of chemical treatment, amount of molluscicide use and labor costs of chemical treatment were estimated in molluscicidal tests in paddy fields, and the costs of chemical treatment for an area covering 667 m2 by drones and manual applications were calculated. Results　The mortality of P. canaliculata snails was all 100% in plots 3 days and 7 days following spraying WPPS at doses of 0.50, 1.00, 2.00 g/m2 and 4.00 g/m2, and the mortality rates of P. canaliculata snails were 66.67% to 100.00% 3 days post⁃treatment with SCPS at various doses ([χ2] = 277.897, P < 0.05) and 76.67% to 100.00% 7 days post⁃treatment ([χ2] = 274.206, P < 0.05). The mortality rates of P. canaliculata snails were 98.19% to 100.00% 3 days post⁃treatment with WPPS at various doses in paddy fields. There was a significant difference in the mortality of P. canaliculata snails among WPPS treatment groups and controls ([χ2] = 270.778, P < 0.05), and there were no significant differences between WPPS treatment groups and the chemical control group (all P values > 0.05), while there were significant differences in the mortality of P. canaliculata snails between WPPS treatment groups and the blank control group (all P values < 0.05). The mortality rates of P. canaliculata snails were 89.83% to 95.31% 3 days post⁃treatment with SCPS at various doses sprayed with drones, and there was a significant difference in the mortality of P. canaliculata snails among SCPS treatment groups and the blank control group ([χ2] = 1 132.892, P < 0.05). There were no significant differences in the mortality of P. canaliculata snails among SCPS treatment groups or water mixture groups (all P values > 0.05), and there were significant differences in the mortality of P. canaliculata snails between SCPS treatment groups and the blank control group (all P values < 0.05). The mortality rates of P. canaliculata snails were 94.62% to 100.00% 7 days post⁃treatment with SCPS at various doses sprayed with drones, and there was a significant difference in the mortality of P. canaliculata snails among SCPS treatment groups and the blank control group ([χ2] = 1 266.932, P < 0.05), with the highest mortality found following spraying 0.50 g/m2 SCPS mixed in 2 kg/667 m2 water with drones (P < 0.05). The costs of P. canaliculata snail control by drones and manually were 35.85 Yuan/667 m2 and 43.33 Yuan/667 m2; however, the snail control efficiency was 6.67 times higher by drones than by manual applications. Conclusions　SCPS sprayed with drones is highly active against P. canaliculata snails in paddy fields. SCPS sprayed with drones is highly efficient and low in cost for P. canaliculata snail control in paddy fields, beaches and river courses.

Key words: Pomacea canaliculata, Pyriclobenzuron, Drone, Suspension concentrate formulation, Wettable powder formulation, Mortality, Molluscicidal cost

摘要： 目的　评价在稻田环境中采用无人机喷洒20%吡螺脲硫酸盐悬浮剂（pyriclobenzuron sulphate suspension concentrate，SCPS）杀灭福寿螺的效果与成本，为吡螺脲在福寿螺控制领域的推广应用提供参考。方法　2022年7月，选择江西省南昌市某块水稻田作为试验区，在试验区设置72块面积为2 m × 1 m的长方形独立试验小区，各小区间隔1 m，于每小区轻轻放置20只福寿螺成螺。选取54块小区开展25%吡螺脲硫酸盐可湿性粉剂（pyriclobenzuron sulphate wettable powder，WPPS）灭螺试验，分别设0.50、1.00、2.00、4.00 g/m2 WPPS组，药物对照组和空白对照组，每组9个小区。0.50、1.00、2.00、4.00 g/m2 WPPS组分别人工喷洒相应浓度药液，药物对照组以人工喷洒0.1 g/m2 的50%氯硝柳胺乙醇胺盐可湿性粉剂（niclosamide ethanolamine salt wettable powder，WPNES），空白对照组人工喷洒等量清水。选取剩余的18块小区开展SCPS灭螺试验，基于WPPS试验结果，分别设0.20、0.30、0.40 g/m2和0.50 g/m2 SCPS组，药物对照组、空白对照组，每组3个小区。0.20、0.30、0.40 g/m2和0.50 g/m2 SCPS组分别人工喷洒相应浓度药液，药物对照组以人工喷洒0.1 g/m2 WPNES，空白对照组以人工喷洒等量清水。2023年7月，选择江西省鹰潭市余江区福寿螺活螺平均密度> 5只/m2的14块水稻田作为试验区进行大田灭螺试验，根据小区灭螺试验结果设置0.25、0.50、1.00 g/m2 人工喷洒 WPPS组，0.25、0.50、1.00、2.00 g/m2 人工拌土施撒WPPS组，药物对照组、空白对照组，每组1块试验田。人工喷洒WPPS组、人工拌土施撒WPPS组分别以人工喷洒和拌土施撒的方式施用相应浓度药物，药物对照组以人工喷洒0.1 g/m2 WPNES，空白对照组以人工喷洒等量清水。根据小区灭螺试验结果，按照SCPS施药浓度分别为0.25、0.50 g/m2、兑水量分别为2、4 kg/667 m2设置4组SCPS施药组，分别采用无人机喷洒相应剂量SCPS；另设1组空白对照组，以无人机喷洒等量清水。小区及大田试验均于施药后3 d和7 d捕捉福寿螺并鉴定死活，计算福寿螺死亡率及校正死亡率。统计大田灭螺试验中各组施药面积、药品用量、施药人工费等，分别计算无人机和人工施药每667 m2的灭螺成本。结果　小区试验中，0.50、1.00、2.00、4.00 g/m2 WPPS施药后3 d和7 d福寿螺死亡率均达100%。SCPS喷洒施药后3 d和7 d，各剂量组福寿螺死亡率分别为66.67% ~ 100.00%和76.67% ~ 100.00%，各剂量组、对照组间差异均有统计学意义（[χ2] = 277.897、274.206，P均< 0.05）。大田试验中，WPPS施药后3 d，各剂量组福寿螺死亡率为98.19% ~ 100.00%，WPPS各剂量组、各对照组差异有统计学意义（[χ2] = 270.778，P < 0.05）；WPPS各剂量组与药物对照组福寿螺死亡率差异均无统计学意义（P均> 0.05），与空白对照组差异均有统计学意义（P均< 0.05）。采用无人机喷洒SCPS后3 d，各剂量组福寿螺死亡率为89.83% ~ 95.31%，各剂量组及空白对照组差异有统计学意义（[χ2] = 1 132.892，P < 0.05）；不同剂量和兑水量SCPS组福寿螺死亡率差异均无统计学意义（P均> 0.05），但均与空白对照组差异有统计学意义（P均< 0.05）；施药后7 d，各剂量组福寿螺死亡率为94.62% ~ 100.00%，各剂量组及空白对照组差异有统计学意义（[χ2] = 1 266.932，P < 0.05），其中0.50 g/m2 SCPS兑水2 kg/667 m2组福寿螺死亡率最高（P < 0.05）。无人机和人工喷洒面积均为667 m2时，灭螺成本分别为35.85元和43.33元，且无人机作业效率为人工的6.67倍。结论　无人机喷洒SCPS可高效杀灭稻田福寿螺，在稻田、洲滩、河道等环境采用无人机喷洒SCPS具有较高灭螺效率和较低灭螺成本。

关键词: 福寿螺, 吡螺脲, 无人机, 悬浮剂, 可湿性粉剂, 死亡率, 灭螺成本