为分析易感地带灭螺后钉螺回升及感染性螺增加的原因。1986年,对已连续四年灭螺后的君山农场七分场外洲的易感地带的钉螺、耕牛(抽取部分)、野粪、洪水期渔民的粪便进行了调查。洪水期在交界点上,选择深、稀、无、矮芦苇处4个点设置尼龙绢网袋(60目/时),观察钉螺从未灭螺区向灭螺区扩散的情况。 To analyze the susceptible zone snail snail snail recovery and infection after the snail increase. In 1986, surveys were conducted on the excrement of snails, cattle (drawn portions), wild manure, and fishermen during the flood season in the susceptible areas of Junshan Farm in Junshan Farm, which has been under continuous snail control for four years. Flooding at the junction, the choice of deep, thin, no, short reed at 4 points set nylon tulle bag (60 mesh / hour) to observe the snail from the area of ​​non-destroying snail area to spread.