@article{oai:nagoya.repo.nii.ac.jp:00015376,
 author = {MAKIYA, KIYOSHI and ISHIGURO, TORAO},
 issue = {3-4},
 journal = {Nagoya Journal of Medical Science},
 month = {Mar},
 note = {Population study was made on Austropeplea ollula (Gould), the snail intermediate host of avian schistosomes which caused paddy field dermatitis. from the viewpoint of successive changes in the size of the snails in the field in relation to the occurrence of the dermatitis. The growth of the snail host was observed by analyzing the shell-size distributions of summer and overwintering populations. Young snails born in autumn composed the overwintering population in rice stubbles, and appeared on the soil surface in spring season after irrigation water was introduced into the paddy fields. During the first breeding season in early summer, the snail population on the soil surface consisted of two different size-groups, i.e., a few large snails which overwintered in rice stubbles and a majority of small ones produced by the overwintered snails. During the period from May to October, breeding of the snails was observed twice, first in early summer and again in autumn. The large snails, which were more likely to harbour the cercariae, were found in May-June, August and October, but their density was low in August and October due to draining of the paddy field as a step in rice farming. In consideration of these circumstances, the large snails found in May-June were suggested to be responsible for the occurrence of the dermatitis. Accordingly, snail control measures should focus on the large snails which overwinter in paddy fields.},
 pages = {47--55},
 title = {Population Studies on Austropeplea Ollula (Gould), the Snail Intermediate Host of Dermatitis-producing Avian Schistosomes},
 volume = {44},
 year = {1982}
}