A SEASONAL CHANGE OF THE AGE COMPOSITION IN A POPULATION OF THE PSEUDOSCORPION, NEOBISIUM (PAROBISIUM) PYGMAEUM (ELLINGSEN), IN A TEMPERATE DECIDUOUS FOREST

Abstract

The age composition in a population of the pseudoscorpion, Neobisium (Parobisium) pygmaeum (ELLINGSEN), was studied every month. A total of 273 individuals including 66 protonymphs, 65 deutonymphs and 142 tritonymphs were collected from the study site in Shimozuma, Ibaraki Pref. in central Japan, during the study period from May 15, 1978 to June 28, 1979. A seasonal change was presumed in the number of nymphs in each stage. Some remarks on the life cycle of this species in the present population were also made.