DDB makes a data entry form available which you can use to calculate the growth factor of the Varroa population in spring. Based on this growth factor you can decide whether to use the colony in a selection programme or not. A low growth factor indicates that the colony has found some means to suppress Varroa reproduction. A high growth rate indicates that the bees cannot cope with Varroa growth and should be treated in order to survive. DDB recommends not to use these colonies if you want to reduce or even eliminate completely the use of control products or measures in the longer run.
In the column marked yellow counting data can be entered at the line holding day and date. For each separate colony use a different column. Normally it would be sufficient to count once per three or four days.
The data in the yellow column are used for the calculation. For the various colonies you would have to copy the data into this yellow column first. The programme then calculates the various curves, the shape of which is visible under the various tabs.
Download the form here (in Dutch).