Is really bad idea use Apistan for more time that 42 days? HEre somepoeple are making using for many more times, maybe 45 days but 3 times or at minimum 2 times in the year. What isthe harm for this? Thank You for your answer.
Mites will eventually become resistant to Apistan. If you leave it longer in the hive, it will only help those who have natural resistance to breed that much longer.
Not only that but, if you leave it in the hive the active ingredient ( fluvinate) becomes much weaker and those mites that wern't resistent befor now have a chance to become resistent.