If you're looking to boost population of these NUC's there's a couple ways to do so.
1. If adding frames to the NUC. Make sure you get one with Capped Older brood starting to emerge if you can. These i've found are darker brown than just recently capped brood. The boost you will get from young nurse bees is great, as well as it opening up area for the new queen to lay in.
2. If only needing to add more bees. What I do is find a frame that has had mostly capped brood that has emerged. Usually the younger nurse bees from that frame will hang out on it for a time prior to moving through the hive. The young is what you need in a NUC to start with, as the older bees that helped create the queen will become foragers.
I hope this helps. It's what I do with mine.
1. If adding frames to the NUC. Make sure you get one with Capped Older brood starting to emerge if you can. These i've found are darker brown than just recently capped brood. The boost you will get from young nurse bees is great, as well as it opening up area for the new queen to lay in.
2. If only needing to add more bees. What I do is find a frame that has had mostly capped brood that has emerged. Usually the younger nurse bees from that frame will hang out on it for a time prior to moving through the hive. The young is what you need in a NUC to start with, as the older bees that helped create the queen will become foragers.
I hope this helps. It's what I do with mine.