Amin M A, Fenwick A
Ann Trop Med Parasitol. 1975 Jun;69(2):257-64. doi: 10.1080/00034983.1975.11687008.
Using a crop-spraying aircraft modified to give a coarse spray, the feasibility of aerial application of the molluscicide N-trityl morpholine to minor canals on the Gezira has been proved. In January 1973, seven canals were sprayed at dosages of 0-1 p.p.m., 0-2 p.p.m., 0-5 p.p.m. and 1-0 p.p.m. Chemical analysis indicated that about 70% of the chemical was present in the water 5-15 hours after the spray, and snail exposure to the sprayed canals indicated that all dosages applied were lethal to Biomphalaria snails. Bulinus snails, which are less susceptible to the molluscicide, were killed only by the 0-5 p.p.m. and 1-0 p.p.m. dosages. Sampling of the natural snail populations of the canals confirmed these results. In March 1973, an area of 464 sq km was treated by drip-feed of 0-1 p.p.m. N-trityl morpholine to kill snails in the main and major canals, and then by aerial spraying 56 of the 58 minor canals in the area. Despite the high winds which disrupted the spray timetable, the canals were successfully treated in 9-5 hours flying-time within seven days. A very high initial snail kill was indicated by both caged snail exposure and natural snail population sampling. However, in excellent snail breeding conditions the area was reinfested with snails within two months. The cost of the application was only 5% of the chemical cost, and aerial spraying in March and May will almost certainly be incorporated in an annual snail control programme.
通过使用一架经过改装以进行粗喷雾的作物喷洒飞机，已证明在杰济拉地区的小运河上空喷洒杀螺剂N-三苯甲基吗啉是可行的。1973年1月，对七条运河分别以0.1 ppm、0.2 ppm、0.5 ppm和1.0 ppm的剂量进行了喷洒。化学分析表明，喷洒后5至15小时，约70%的化学药剂存在于水中，而将蜗牛暴露于喷洒过的运河中表明，所施用的所有剂量对双脐螺均具有致死性。对杀螺剂不太敏感的泡螺，只有在0.5 ppm和1.0 ppm剂量下才会被杀死。对运河自然蜗牛种群的抽样证实了这些结果。1973年3月，通过滴灌0.1 ppm的N-三苯甲基吗啉对464平方公里的区域进行处理，以杀死主运河和主要运河中的蜗牛，然后对该区域58条小运河中的56条进行空中喷洒。尽管大风打乱了喷洒时间表，但在七天内仅用9.5小时的飞行时间就成功地对运河进行了处理。笼养蜗牛暴露试验和自然蜗牛种群抽样均表明最初的杀螺效果非常高。然而，在极佳的蜗牛繁殖条件下，该区域在两个月内就再次出现了蜗牛。施用成本仅为化学药剂成本的5%，3月和5月的空中喷洒几乎肯定会纳入年度蜗牛控制计划。
