Quantitative sampling of the pseudoscorpion Chthonius ischnocheles from beech litter

Samples of beech litter were taken from a site in Lambridge Wood, near Henley-on-Thames, Oxon. during the period May 1963 to November 1964. Peaks and trends in the densities of each of the stages of C. ischnocheles clarify the earlier work of Gabbutt & Vachon (1963) especially for the postwinter period. Most of the protonymphs appear during July to September and the majority overwinter as deutonymphs. Growth recommences the following spring, peak densities of tritonymphs are achieved in May to June and maturity is attained July to August. Mortality in the prewinter period is at least 85% and about 50% occurs during the protonymphal stage. The adults in August belong to at least two different generations. about 40% have recently matured, the remainder have bred at least once before. Mention is made of the densities achieved by both N . muscorum and R. lubricus in relation to the very high overall densities recorded on the site.