水田の水生昆虫の季節的消長

概要

論文の詳細を見る
In 1978,faunal composition and population density of aquatic insects and tadpoles in irrigated paddy fields were studied by using the plastic pan water trap, by the direct observation, and by sweeping, in Kochi Prefecture. The aquatic insects trapped were dominated with Bidessus japonicus (Col.) and Microveria douglasi (Hem.) and the fauna was simple. Sympetrum frequence (Odo.), Gerris lacustris (Hem.) and Berosus vesticus (Col.) were collected in an earlier season, while Orthetrum albistylum specicum (Odo.), Pantala flavescens (Odo.) and Microveria douglast were abundant in a later season, Bidessus japonicus was abundant throughout the seasons. As rice plant grew taller with more tillerings, the total number of insects per m^2 increased, while egg colonizing species (Odonata and Ephemeroptera) and tadpoles disappeared, as a result the diversity of insect fauna decreased irrespective of the date of planting time. In a thinly planted field, even such egg colonizing species persist until late due to availability of water surface between rice canopy and the diversity remained constant. So it is condsidered that this change in the fields planted in ordinary density is due to the covering of water surface by the grown rice plant. The later the planting date was, the higher the initial density of insects was.
日本生態学会の論文
1980-12-30