抄録
The possible domestic migration of the white-backed planthopper, Sogatella furcifera, in Japan was investigated. The next emigrating generation of immigrants during the Bai-u rainy season was selected for analysis. Four criteria were used to determine whether a migration was domestic: 1) a large catch peak in the net trap in northern Japan, 2) in the trap area, the absence of a preceding generation of catch insects based on the analysis of effective accumulated temperature, 3) suitable air currents for insects to migrate from western to northern Japan, as found by backward trajectory analysis, and 4) the presence of emigrating adults in rice fields in western Japan based on a field survey of the population density. The catch data obtained from a net trap in Akita city, Akita prefecture, from 1980 to 2006 showed four clear peaks exceeding 1,000 insects per day, and only one of these, occurring in early August 1987, was found to meet all criteria. The weather pattern was a low-pressure system in the Japan Sea moving northeastward, with a windy region from western to northern Japan. The possible effect of domestic migration in early August on rice crops in northern Japan was discussed.
