Colony weight (kg) and number of brood (frames/ hive) of local and non-local colonies over time (days after requeening). (A) Colony weight measurements commenced 11 days after requeening the colonies and were measured every 15–20days for a total of four measurements. (B) Frames of brood in colonies were first measured four days before we requeened the colonies and were measured approximately every 14days, for a total of five measurements. Varroa mites were treated for using 75 mL of 1.11 specific gravity formic acid 15 days after requeening (arrow).