Efficiency of Bs treatments under operational field conditions. Bs application took place on day 0, day 7 and day 14 (arrows). WDG formulation was applied on day 0 and 7; CG formulation was applied on day 14. Differences in immature densities were analysed using Mann-Whitney tests at a significance level of p < 0.05. Different letters (a, b) on bars indicate a significant difference at the specific sampling date.