抄録
An outbreak of Japanese B encephlitis took place in 1953 at an unusual early date (June) in a limited area in the city of Kurashiki. Our observation which we have been conducting since 1950 on the seasonal occurrence of mosquitoes in Okayama City has shown that the increase of population of mosquitoes, especially of Culex tritaeniorhynchus, would have some correlation with the outbreak of B encephalitis. Based on this finding we expected that there might be a certain correlation between the early outbreak of the encephalitis and early activity of this mosquito in this particular area, but so far as our investigation by light-trap is concerned no definite conclusion has been reached.
