[Investigation on historical snail environments in Taizhou City].

OBJECTIVE: To understand the status of historical environments of Oncomelania snails in Taizhou City, Jiangsu Province and evaluate the current condition of snail control. METHODS: The historical files of snail distribution were reviewed, field investigations were conducted, and all the data were analyzed. RESULTS: Totally 7 822 historical snail environments were identified, the total area with snails were 4 252.98 hm2. According to the degree of environment reformation, all historical environments were classified to I, II, III, IV types, and the proportions of the Type I, II, III, IV were 28.3%, 2.4%, 19. 4%, 49.9% respectively. There were 2 snail environments currently, with total area of 3.60 hm2. CONCLUSION: The snail status has been under well controlling, but most of the historical environments are suitable for snail breeding. Therefore, it is necessary to continue the snail surveillance.