When virgins emerge they kill queens. If they don't kill the older queens, then the hive/nuc swarms and the established queen usually leaves with the swarm. If you want to save your introduced queens, then destroy all the queen cells.
You left the boxes queenless for 2 days before introducing queens. By that time, the existing bees had already started queen cells. I myself try to never let a box be left queenless more than one day, and usually just ten minutes to a few hours, when introducing queens. The bees know within ten minutes that they are queenless when you remove a queen. Within 20 minutes to an hour or two they start roaring. When they are roaring, they will accept a queen introduced with great passion and fanfare. They instantly calm and mellow out.
You left the boxes queenless for 2 days before introducing queens. By that time, the existing bees had already started queen cells. I myself try to never let a box be left queenless more than one day, and usually just ten minutes to a few hours, when introducing queens. The bees know within ten minutes that they are queenless when you remove a queen. Within 20 minutes to an hour or two they start roaring. When they are roaring, they will accept a queen introduced with great passion and fanfare. They instantly calm and mellow out.
