Fig. 4.
a Dynamics of the numbers of adult Chaoborus crystallinus collected in emergence traps placed in mesocosms treated twice (days 0 and 14) with different concentrations (0–5.0 μg/L) of an insecticide. b Dynamics of the numbers of adult Chironomus sp. collected in emergence traps placed in mesocosms treated twice (days 0 and 21) with different concentrations (0–30 μg/L) of another insecticide. Shown below each panel are the calculated %MDDabu and NOEC values for each sampling day. If a NOEC is placed between brackets, this means that the corresponding %MDDabu value is >100 % and a proper NOEC for treatment-related decline cannot be derived