There are some beekeepers that have managed to keep their Apis mellifera mellifera bees for years without treating them for varroa. Not all bee populations will manage to survive without treatment though. In order to get an idea of how your colonies are doing it is advisable to count the natural varroa mite downfall on the bottom board.
- In Finland the following protocol is used to find out if the colony needs to be treated:
- Count and write down the number of dead mites on the bottom board over 7 to 10 days.
- In the spring: If you find more than an average of 1 mite per day you should consider treating the colony.
- In the fall: If you find more than 15 mites per day, you should consider treating the colony.
The different treating thresholds are due to the mites' and bees' population dynamics and their life cycles.
PICTURES JAOCHIM of a varroa mite, of the bottom board of lars checking his clean board.