予察田におけるツマグロヨコバイの分布と発生消長

抄録

1. The experimennt was carried out every 10 days to clarify the distribution and population density of the green rice leafhopper in the four paddy fields trnsplanted on respective dates,
2. In the fields transplanted on May 8 and May 26, nymphs immigrated into the fields from the surrounding grass in levee, thus density of adult population of the first generation concentrated extremly to the marginal parts of the fields.
3. In the case of new generation after immigration, both nymph and adult distridutions were heterogeneous having one or several dense patch. And then numerical population of the insect increased gradually covering all parts of the fields.
4. The adults of the second generation in the fields transplanted on May 8, appeared as much as 20-30 days earlier than that in light trap catch.