The results from the probit analysi

The results from the probit analysis are presented in Table 1. The response of the reference strain GR-LAB fifitted the log-dose probit-mortality model, while the fifield-collected strain Bt496 exhibited heterogeneity as indicated by the high X2 values. The LC50 values of strain Bt496 to flflupyradifurone exhibited a threefold difffference when compared to the reference strain; however, such difffferences are considered expected within the range of natural variability. The response of Bt496 to thiamethoxam was comparable to that of the reference strain. The strain could be considered susceptible to both insecticides. Based on the LC95 values the recommended label rate for flflupyradifurone (150 mg L−1) could achieve mortality levels equal to or higher than 95% for both tested strains. This was not the case for thiamethoxam; the mortality levels for Bt496 were expected to be signifificantly lower than 95% at the recommended rate (75 mg L−1) since the 95% fifiducial limits of LC95 ranged between 97 and 2886 mg L−1. The LC95 value for the susceptible strain was 35 mg L−1, lower than the thiamethoxam recommended rate.