THE BIOTIC COMMUNITY IN THE WATER-FILLED INTERNODE OF BAMBOOS IN NAGASAKI, JAPAN, WITH SPECIAL REFERENCE TO MOSQUITO ECOLOGY

Abstract

The biota in the water-filled internode of live bamboos was periodically sampled for a year in Nagasaki, Japan. At least 40 species of Metazoa were collected. The larva of a Dasyhelea KIEFER species (Ceratopogonidae), and that of Culicidae, Oribatidae, Formicidae, and Collembola were most abundant in this order, of which only the dipterous larvae were aquatic. The culicid larvae included Topomyia yanbarensis MIYAGI and Tripteroides bambusa bambusa (YAMADA), of which the former were dominant. Bacteria, Fungi Imperfecti, and Protozoa were also common in the water. The larva of Dasyhelea species was found throughout the year. Also, To. Yanbarensis larvae were collected all year round except midwinter when only dead bodies were found. No preference for the height of internodes was recognized for these Diptera species, at least in the range examined (up to 1.7 m above the ground). The Topomyia distribution per internode changed from contagious in the eggs to uniform in the 4th instar larvae via the random in the intermediate developmental stages. A single 4th instar larva usually occupied a single internode. Tr. b. bambusa increased in number when Topomyia density was low. This species occurred exclusively in the internodes near the ground.