Preliminary Observations on the Life History of Two Polistine Wasps, Polistes Snelleni and P. biglumis in Sapporo, Northern Japan (With 9 Text-figures and 3 Tables)

Abstract

The descriptions are mainly based upon the periodical observations made at the foot of Mt.Hakken-zan from April to October, 1968 made at irregular intervals of 3 to 12 days.Additional data taken during 1962~1968 at Tsuneji-zawa, Bankei and Hoheikyo, all in the vicinity of Sapporo, are also incorporated when necessary.Nests observed at Hakken-zan first consisted of 38 nests of P. snelleni and five of P. biglumis.Caused by the subsequent evacuation or destruction, the number gradually decreased.The nests continued until the fall were only three in P. snelleni and two in P. biglumis.The following descriptions are given mainly based upon these successful nests.Some notes on the unsuccessful nests are given at the end of the results.