Reserves of the colonies at the beginning of the trial

It is necessary to reduce as much as possible the content of previous food reserves in hives so that the exposure to the AI present in the field can be maximised. That is why one could  remove the frames containing mainly food reserves from colonies before the crop blooms. This could lead colonies to starve in the days immediately following the removal of the food. Consequently, the health of the colony should be monitored closely.