I placed some sticky screens under the brood box's and left them in for 3 days, i have now removed them, one hive had 4 mites and the other had 9 mites, Both hives were treated with Apiguard in September, Today its 12 degres and bees are flying and bringing in Pollen from Ivy.
Is there a formula for working out the infestation levels during winter as i cannot do sugar roll with 300 bees this time of year.