ReQueening Advise Needed

[BeeHopper]

I have to requeen 2 hives AGAIN  :(
But I am not sure how to approach it this time, so I am asking the HiveMind for advise.
Here is the timeline:
April 22- Destroyed both 2nd year Buckfast Queens, immediately introduced Italian Queens. Note: the Buckfasts were still prolific and fat. I should have waited till fall to requeen.
April 29- Activity at hive entrance was very busy as usual, I felt there was no need to enter hive at this time.
May 13- Entered hive to remove Queen cage, the workers were hotter than usual, closed it up immediately.
May16- Noticed very little activity at hive entrance. I am now concerned.  :?
June 2- Opened both hives. No queens nor queen cells, no brood, mostly open comb filled with nectar and pollen on all frames. There are some white capped areas of honey at the tops of frames( Normal). I cannot determine if there a laying worker because I cannot find eggs, however there are a ton of drones.

What would you do and how considering there are plenty of workers and stores in both hives  :?

[Brian D. Bray]

You just named one of the reason I do not requeen yearly.  Why get rid of 2 well functioning queens?
I well sometimes replace supercedure queens the 2nd year.  But overall I expect 3 years out of a good queen.  Sounds as if you killed your queens and then tried to requeen before the bees were fully aware the destroyed queens were missing.  They well destroy a queen in a cage if they think they already have a queen.  Then you end up queenless.  That is a good reason to have a nuc with a queen handy.

If no eggs you probably have not yet developed a laying worker.  I would put in a frame of eggs/larvae from another hive if you have one.  What each of the hives does with the frame of brood will tell you how to progress.

I find it a good rule to never put a new queen in a hive until it has been queenless for at least 24 hours. 

[Mici]

a word pf advice, when requening, and you know the queen is still doing a good job, don't kill her, keep her in a cage with few attendants.

[BeeHopper]

I was having second thoughts at the time I was destroying 2 good queens ( lesson learned ). I have heard, not experienced that the Buckfasts make a very hot queen on their own. I have done some research today to see what I can do differently. I will spray the hive and the queen with  some sugar water w/ lemongrass oil to mask her scent during the introduction.They should acept her now that they have been without one for a month. I will also double check for a laying worker beforehand. thanks for the input  :-D