It appears that my hive is queenless and there are queen cells with larva in it. It appears there is less population. I bought new queen which i put in between the frames in a cage. Do I have to destroy queen cells, and what to do to improve acceptance?
They won't accept a new queen unless they are hopelessly queenless. You need to destroy queen cells and then in 10 days go into hive and destroy cells again. If they have a way to make a queen they won't accept new queen. Or you could let them make their own queen. This has been my experience.