Some takeaways for me ~
Reverse hive bodies not only once in spring, but multiple times throughout the season. Mike suggested every 10 - 20 days. Assuming that the queen is laying eggs in the upper box prior to the reversal, she will now be laying in the bottom box. When that box is full she will move up into the next box, which was the bottom box. While she's laying in the upper box bees are emerging in the bottom box and vacating cells. When the cells are full in the upper box the colony will start to think about swarming. But if the boxes are again reversed, there will again be empty cells above. But the reversal needs to occur prior to swarming mode.
Once the bees have decided to swarm, they're going to swarm. If swarm cells are found on the bottom of frames, the colony can be split to simulate swarming and keep the bees, now in two hives. Mike's suggested method for making a split is to put a queen excluder between the hive bodies and then check for the presence of eggs after 3 days. The box with the eggs is the box with the queen. That box stays in its location and becomes the honey producing colony. Add a second deep (if you're using the two deep hive method) on top of the box with the queen and add supers when the second box is 80% full.
The second, queenless hive, needs to be placed at least several feet from the mother colony and fed syrup. This hive should remain queenless for at least 24 hours prior to introducing a new queen. Since commercial queens are not available until very late April or early May, don't start the split before you know when you'll be receiving a new queen. Or wait until our local queen breeders have stock of northern queens around early June.
You can also let the bees make a queen, but for that you need larvae, no older than 3 instar (3 days after hatching). A frame with eggs and larvae can be switched with another frame from the split, but it will take around 45 days afterwards before new bees will emerge......if all goes well. And make sure the queen isn't on the frame of eggs and larvae that you're switching (which is probably right where she is). This split is an increase hive and may not produce honey in the same season that it's started. The focus should be on building up for winter.
Mike's preference for introducing queens is to place the caged queen in the hive for 3 days with a cork in the hole. After three days he does a direct release on to the tops of the frames. If the bees don't nip at her and attack her he lets her go. If they do attack her, he'll recage her for a day and try again.
Mike spent some time on Varroa and the current treatments available. He is very excited about oxalic acid as he feels it does the least damage to the bees. It can only be used during cool temps (30 - 50 F) and that corresponds with the broodless, or very low brood, periods in spring and fall. His preference is the drip method. He feels that's the safest method for the bees and the beekeeper. He also encourages the use of, and breeding of, hygienic queens to combat Varroa.
- When adding foundation, put a box of drawn comb above the box of foundation (if you have one) so the bees have to pass through the foundation to store honey.
- Feed syrup when foundation is added unless there is a strong nectar flow.
- When adding supers with mixed drawn comb and foundation, keep the drawn comb and foundation together. Don't checkerboard the frames.
- Do NOT use Fumagilin. It does nothing to the nosema spores.
- Currently a 4% mite count is considered high.