Apistan

[Nahl]

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.

[Lesli]

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.

[Apis629]

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.