Collection and analysis of data

1) For both tests (mobile cage and free flight), the comparison between bee survival at the beginning of the trial, i.e. before the start of drilling and after every 15 minutes is obtained (for a maximum of four samples, but are sufficient two samples).

2) To compare different bee samples (treatments, humidity levels and collection times), the null hypothesis that the mortality is independent on the considered parameters should be tested using a chi-squared goodness-of-fit test.

3) To verify the influence of relative humidity, the cages with the bees, are randomly divided and held in laboratory or high humidity (see section

4) In the mobile cage test, the distance from the driller, which causes no acute bee mortality, also can be estimated.

5) This method of bee mortality evaluation in the field (in particular the mobile cage) is an innovative biological test that can be applied to verify the efficiency of driller modifications.