Adult,healthy and individually weighed L. terrestris from a
particular geographical origin were randomly selected and introduced
into six tubes,so that altogether there were 3 (origins) 6
(replicates) = 18 experimental tubes,each containing three earthworms.Transparent,
0.1 m tall,plastic collars were mounted on top
of the tubes to deter earthworm escape.Two tubes were kept
without earthworms for monitoring experimental conditions.After
earthworm addition,but prior to the experiment,all tubes were
kept for one week at +15 C in a 12:12 hartificial light cycle,with
lights on at 23:00 h and off at 11:00 h.This was to equally distort
possible emergence patterns originating from the different longitudinal origins of the populations.