Field studies are more difficult to conduct than semi-field and laboratory studies. One of the main critical points concerns the replicates. In fact, it has always been affirmed that one replicate consists in more colonies located in a single area. Nevertheless this assertion is controversial. In fact, in a field study it is always very difficult to replicate the same environmental conditions in independent trials (it is necessary to have no interference between treated/untreated colonies and replications). For these reasons, in the field every single colony needs to be considered a replicate. In this way, a field experiment using about 10 colonies per apiary can be considered adequate. Furthermore, if it was impossible to find two experimental fields in the same conditions for the comparison of the treatments, then it should be allowed to perform the test on a single plot (before and after the chemical treatment in the same field).