Abstract
The fundatrigenia of Moritziella castaneivora dispersed twice in summer during the growing period of chestnut burs in Kyoto Prefecture. Firstly, some nymphs of the second generation moved toward the base of chestnut cones from the branches, where the fundatrix and first generation of fundatrigenia grew up, in late June. The first peak of occurrence was discernible at the end of August as a result of the successive generations, and serious damage (green chestnut bur-burst) was caused by them. Thereafter, the first instar crawlers of the fourth or fifth generation on the chestnut cones dispersed round the trees, and the second peak appeared in early September. This second dispersal was observed by using sticky traps, and the daily dispersal activity was high in the afternoon. The first instar nymphs were seen to crawl about 4cm per minute on paper and to survive only for about 5 hours without the host-plant. The dispersal among the trees, therefore, was restricted within a narrow area of the field.
