Seasonal fluctuation of population density of spiders in paddy field in Kyoto City

[摘要] References(11)Population density of spiders investigated in a paddy field in Kyoto City from May to November in 1975. Micryphantidae and Lycosidae were dominant in the paddy field and levee. Spider population in the paddy field showed 2 peaks in mid August and in mid October; particularly, it amounted to 200 individuals per m2 in mid October. On the levee, it showed a sawteeth-like curve with 3 peaks, amounting to 140 individuals per m2 in mid July and in mid October. Similarity of spider fauna between the paddy field and the in cultural period of rice crop was about 60%.In the consequence of examination on the larval percentage of dominant species, it seemed that the spiders passed the winter in the form of adult in Micryphantidae (=Erigonidae) and in the form of larva in Lycosidae.Oedothorax insecticeps has two generations in a year (TANAKA, 1973); a large number of the adult occur in early July and in early November.In the stage of adult and of subadult, female population appeared abundantly from June to July and from October to November.

[学科分类] 动物科学