from the release point. The increased mortality in the treated trials
compared to the untreated also supports the assumption of a large
number of parasitoids finding the host-patches, because parasitoidinduced
mortality like host feeding and superparasitism typically
increase the mortality of the hosts (Hansen and Jensen, 2002). We
followed the current recommendation of 1000 T. evanescens per m2
and week for empty room treatment with T. evanescens, and our
data support the validity of this recommendation. The parasitism
did not change over the three-week period, indicating a continuous
emergence of the parasitoids from the release unit