The mating frequency data set was small , but sufficient to
demonstrate that white night conditions limit mating of dew-
worms.One explanation for this may relate to the pre-mating
behaviour of this species.Preceding mating, L.terrestris go
through a courtship sequence on the soil surface that in volves
burrow visiting (NuutinenandButt,1997)and evaluation of partner’s
size(Michielsetal.,2001).The length of this sequence varies,
but it can take up to 90 min(NuutinenandButt,1997).According to
our own observations ,during the pre-mating sequence dew-
worms are sensitive to light and it is possible that the period of
low illumination under ambient light was often not long enough to
allow the successful completion of the pre-mating phase.