In general a colony will replace a failing, underperforming or lost queen fairly quickly themselves as long as there are fresh eggs and drones around. A failing queen can occur anytime from spring right through to autumn and is something the colony will usually rectify themselves naturally without the need for keeper intervention. This is known as Supercedure and is a normal part of honeybee behaviour however there are occasions when the colony may need a helping hand. The following is a simple process for confirming / restoring a queenless colony.
Hive inspections which reveal less brood or eggs than expected for the time of year may indicate a problem with the queen, and will require some immediate action. The first action will be to find whether a queen is present or not, and secondly to plan on how you will restore / save the colony. In early spring there are fewer bees in the hive and finding the queen may not be too difficult, however in mid-season it will can be a challenge finding a queen in a hive full of busy bees.
Knowing the age of the queen helps you determine whether she is failing due to old age or if there is something else wrong. A well fertilised queen will lay well for the first two years, and less so in the third. A queen that has not mated well for any reason may not have the reserves to lay well for the expected period. Before deciding that this queen needs replacing, take a look at the brood frames to establish that there is not an underlying problem with colony health / pest infestation. If you are confident it is a failing queen then check for fresh eggs (eggs freshly laid stand up straight in the cell) and drones present before removing the old queen. The bees will do the rest, choosing a fresh egg and developing an emergency queen from it. Alternately if there is no brood or eggs at all then, after checking for any other underlying problems, introduce a frame of brood and eggs from another hive into the middle of the empty brood nest.
If you are confident the queen is healthy, young enough, and should be laying but isn’t, you should suspect some underlying problem such as old blackened unuseable brood frames or a heavy Varroa mite infestation. Use the disease pages to help careful and detailed examination of frames for signs of abnormalities and recommended treatments.
A colony may become queenless for any number of reasons and at any time during the year. The signs of something being wrong can include unusual / defensive colony behaviour, laying drone eggs only, cells with more than one egg, lack of eggs, queen missing or damaged, queen on the wrong side of the queen excluder. Queens can also be lost through many inadvertent mishaps in the hive, clumsy beekeepers, wasps etc. Use the disease pages to help careful and detailed examination of the hive for signs of abnormalities and treatments before re-queening with a frame of eggs and brood from another hive. Shake the attendent bees off the frame from the donor colony before placing in the recipient colony otherwise they will be attacked as intruders.
Alternately you can introduce a new queen reared elsewhere by placing her in a secure queen cage inside the hive for three or four days to allow the colony to get used to her smell before releasing her. releasing a new queen can be achieved by covering the open end of the cage with a piece of newspaper held on with an elastic band or blocking the open end with a piece of candy. The colony bees having accepted her smell will chew away at these to release her. If you release a new queen straight in to the hive the colony will kill her as an intruder.
Whatever course of action you are taking with your colony, consider all the necessary things that are needed to re-queen the colony: secure hive; clean and useable brood frames; healthy bees; available food; healthy eggs and brood; drones etc.
Timing. Any re-queening should be completed before September. Existing colony bees will only last a few weeks before dying off and time is needed to allow the new queen to start laying and build up brood and boost colony numbers of young bees that will take the colony through winter. Timing is especially important if you are introducing a virgin queen, she will need time and opportunity to mate successfully before commencing laying. If a colony has become queenless late in the season consider uniting the bees with another colony or tipping them out to join your other hives.
Lastly on the topic of queens, a colony without a queen for any length of time may end up with laying workers. A queenless colony will know quickly there is no queen present and ordinary worker bees can and will start to lay eggs after a day or so. The eggs a worker can lay are viable but infertile, the worker having never mated, so the eggs they lay will always hatch as drones. Workers are a different shape and size to a queen and are unable to position eggs as accurately in the cell as a queen. The presence of more than one egg per cell, or eggs attached to the cell walls are a clear indication of laying workers. Unfortunately introducing a new queen in this situation is pretty futile, as the laying worker colony is unlikely to accept any new queen. The normal procedure in this instance is to tip the bees out and hope they join other healthy colonies in your apiary.
There is anecdotal evidence for the successful re-queening of a laying worker colony by moving the whole hive 50 meters or so from its original position, dismantling the hive and brushing every single bee out and off the frames then returning the complete hive empty of every single bee to its original position in the apiary. The cast out bees, but not the laying workers, should return to the original hive which can then be successfully re-queened in a normal manner. An interesting idea which in theory has the potential to work and might be worth a go as long as it's well within season, there's certainly nothing nothing to lose!