Many beekeepers are in denial when I tell them their bees have probably swarmed. A beekeeper will look in the hive and see a large numbers of bees and they think the bees couldn't have swarmed. The thing to realize is, it is the field bees that leave. The bees that stayed behind cannot fly yet and are unable to leave with the swarm. When we are looking at a colony during the day, propably 80% of the field bees are gone at any time during a sunny day. If you looked in a colony a half hour after sunset, you would then see all the bees in the hive. After discussing what their hives looked like, they usually come to agreement that yes their hive did swarm.
How do you know if your bees have swarmed? When the bees swarm, the queen stops laying. Queen cells are made and when the swarm cells are capped the hive swarms. Looking inside a colony that has swarmed this is what you will see:
- Queen cells somewhere in the hive. The queen cells usually on the bottom of the frames but they can be anywhere. As you remove queen cells during inspections, the bees will get tricky and make one where you are not looking.
- Absence of eggs and young larvae. The queen stopped laying, her abdomen shrinks anticipating flying off with the swarm. Usually you will notice only very old larvae or only capped brood.
- The brood boxes are filling up with nectar. The bees that stayed will start foraging as they get to the right age and the nectar they bring back fills the brood boxes.
- Few bees in the supers. Beekeepers blame no honey in the supers on queen excluders. But the real reason is their hive has swarmed. It is the denial thing again.
There is plenty of time for the bees to recover their population before winter. But the hive will not make any excess honey for the beekeeper.
If the hive is light on honey stores in mid August. The honey supers should be taken off and feeding of heavy syrup or ProSweet should start then. Waiting to feed later may make it hard to get enough food into the hive before winter.