No brood colony

I am Andres, a BEEginner from the Philippines. I have a 5month old colony based on the the queen I bought, received and introduced approximately 5 months ago. The colony started with 4 frames of brood of different stages and with small amounts of honey and pollen last June 2005. Due to poor feeding, the colony only grew up to 5 frames. Around 55days ago last September, I started feeding it with around 1kg of 0.6kg of sugar mixed with 0.4kg of water every 2 days then later every 5days. For 55days until last Nov. 15, I have added 4 frames of brood with food. I have placed miticide strip against mites which infested itin the hive. I applied used oil with kerosene on hive stands against ants. The mites have not appeared. Only very few and almost insignificant number of ants have entered the hive. The colony begun to increase in population. But for around 1 week now, in spite of the presence of pollen, sugar syrup in the combs, drones and plenty of drawn but empty combs, not a single egg or brood can be seen. Up to 2 days ago, I still saw the queen walking briskly around a frame.
Could it be the queen I bought was already old? Can you please tell me possible causes? You can also give suggestions.

are you sure that it is the queen you bought
is she marked ?
is there queen combs on some frames ?
perhaps the colony changes her queen ?

Originally posted by jsgros:
are you sure that it is the queen you bought
is she marked ?
is there queen combs on some frames ?
perhaps the colony changes her queen ?

I, together with our caretaker of that lot were our colonies are located, are sure we saw the queen we bought. It is noted in my logbook. We have been identifying and noting our queens for 10 months now. We have been noting the history and locations of our colonies. This particular batch of queens was not marked. We did not see any queen cell on any frames the last time. Yes it is probable the colony changed her queen and we did not notice it.
In case you have time, here is the more detailed history:
Last 17June2004, we received 5 pressumed young virgin queens which we bought from Negros Oriental. We introduced them to our colonies in Batangas next day. 4 of our queens survived. 1 survived for a few days inside the queen cage. After around 7 days, a hole was punched thru the confectioniare covering the queen cage hole of the still initially surviving queen. After a week the said queen was nowhere to be found.
1 of the 4 surviving queens was introduced in this particular colony. After 7 days, the queen was out of the cage. It contained 7 frames. After 2 months, 2 of the 7 frames were vacant.
59 days ago on 19Sept., with the said colony already getting weaker due to undernourishmnet, ant infestation and in danger of getting mite infested by its mite infested neighboring colonies, feeding of this colony with 1kg of sugar syrup (0.6kg sugar mixed with 0.4kg water) every 2 days begun. It was done twice for the 1st 4 days. After that, feeding frequency of 1kg sugar syrup for the said colony have been every 5 to 6 days. On 19 Sept also, 1 miticide strip in that colony was inserted. Likewise, 1 strip each for the 3 other weak colonies and 2 strips each for the 2 colonies with 2 hives each were inserted. All frames not covered by bees from all the colonies were taken out. In this particular colony, around 2-3 empty frames were taken out. On this day, this colony had 6frames of brood and workers.
On 21Sept., a number of dead bees were found on the bottom board of this colony. 1 brood frame from a stronger colony was introduced into this colony bringing it to 7frames of brood, workers and food.
On 28Sept., at least 1 closed brood frame was seen in this colony. All the seven frames were at least covered with workers. At least 2 of the frames were drawn of combs around 1/3 inch from the wax foundation. 1 open brood frame and 2 food frames were introduced to this colony from our stronger colony. On this day, this colony had 10 frames.
The whole of October this colony had brood frames and all the frames have been covered by workers. Frequency of feeding of the quantity of sugar have been the same.
On the last visit and feeding last 15Nov., no more brood nor egg can be found on this colony. She was walking briskly around 1 of the frames. I saw a lot of empty drawn combs. There was no problem with cells to lay eggs in. I saw that there were no more mites. Once in a while, I saw very few ants, but they were insignificant in numbers.
There was no problem with the other 5 colonies. Eggs, open and closed brood were seen. They have been steadily increasing in strength.

Originally posted by jsgros:
are you sure that it is the queen you bought
is she marked ?
is there queen combs on some frames ?
perhaps the colony changes her queen ?

I, together with our caretaker of that lot were our colonies are located, are sure we saw the queen we bought. It is noted in my logbook. We have been identifying and noting our queens for 10 months now. We have been noting the history and locations of our colonies. This particular batch of queens was not marked. We did not see any queen cell on any frames the last time. Yes it is probable the colony changed her queen and we did not notice it.
In case you have time, here is the more detailed history:
Last 17June2004, we received 5 pressumed young virgin queens which we bought from Negros Oriental. We introduced them to our colonies in Batangas next day. 4 of our queens survived. 1 survived for a few days inside the queen cage. After around 7 days, a hole was punched thru the confectioniare covering the queen cage hole of the still initially surviving queen. After a week the said queen was nowhere to be found.
1 of the 4 surviving queens was introduced in this particular colony. After 7 days, the queen was out of the cage. It contained 7 frames. After 2 months, 2 of the 7 frames were vacant.
59 days ago on 19Sept., with the said colony already getting weaker due to undernourishmnet, ant infestation and in danger of getting mite infested by its mite infested neighboring colonies, feeding of this colony with 1kg of sugar syrup (0.6kg sugar mixed with 0.4kg water) every 2 days begun. It was done twice for the 1st 4 days. After that, feeding frequency of 1kg sugar syrup for the said colony have been every 5 to 6 days. On 19 Sept also, 1 miticide strip in that colony was inserted. Likewise, 1 strip each for the 3 other weak colonies and 2 strips each for the 2 colonies with 2 hives each were inserted. All frames not covered by bees from all the colonies were taken out. In this particular colony, around 2-3 empty frames were taken out. On this day, this colony had 6frames of brood and workers.
On 21Sept., a number of dead bees were found on the bottom board of this colony. 1 brood frame from a stronger colony was introduced into this colony bringing it to 7frames of brood, workers and food.
On 28Sept., at least 1 closed brood frame was seen in this colony. All the seven frames were at least covered with workers. At least 2 of the frames were drawn of combs around 1/3 inch from the wax foundation. 1 open brood frame and 2 food frames were introduced to this colony from our stronger colony. On this day, this colony had 10 frames.
The whole of October this colony had brood frames and all the frames have been covered by workers. Frequency of feeding of the quantity of sugar have been the same.
On the last visit and feeding last 15Nov., no more brood nor egg can be found on this colony. She was walking briskly around 1 of the frames. I saw a lot of empty drawn combs. There was no problem with cells to lay eggs in. I saw that there were no more mites. Once in a while, I saw very few ants, but they were insignificant in numbers.
There was no problem with the other 5 colonies. Eggs, open and closed brood were seen. They have been steadily increasing in strength.

Originally posted by jsgros:
are you sure that it is the queen you bought
is she marked ?
is there queen combs on some frames ?
perhaps the colony changes her queen ?

I, together with our caretaker of that lot were our colonies are located, are sure we saw the queen we bought. It is noted in my logbook. We have been identifying and noting our queens for 10 months now. We have been noting the history and locations of our colonies. This particular batch of queens was not marked. We did not see any queen cell on any frames the last time. Yes it is probable the colony changed her queen and we did not notice it.
In case you have time, here is the more detailed history:
Last 17June2004, we received 5 pressumed young virgin queens which we bought from Negros Oriental. We introduced them to our colonies in Batangas next day. 4 of our queens survived. 1 survived for a few days inside the queen cage. After around 7 days, a hole was punched thru the confectioniare covering the queen cage hole of the still initially surviving queen. After a week the said queen was nowhere to be found.
1 of the 4 surviving queens was introduced in this particular colony. After 7 days, the queen was out of the cage. It contained 7 frames. After 2 months, 2 of the 7 frames were vacant.
59 days ago on 19Sept., with the said colony already getting weaker due to undernourishmnet, ant infestation and in danger of getting mite infested by its mite infested neighboring colonies, feeding of this colony with 1kg of sugar syrup (0.6kg sugar mixed with 0.4kg water) every 2 days begun. It was done twice for the 1st 4 days. After that, feeding frequency of 1kg sugar syrup for the said colony have been every 5 to 6 days. On 19 Sept also, 1 miticide strip in that colony was inserted. Likewise, 1 strip each for the 3 other weak colonies and 2 strips each for the 2 colonies with 2 hives each were inserted. All frames not covered by bees from all the colonies were taken out. In this particular colony, around 2-3 empty frames were taken out. On this day, this colony had 6frames of brood and workers.
On 21Sept., a number of dead bees were found on the bottom board of this colony. 1 brood frame from a stronger colony was introduced into this colony bringing it to 7frames of brood, workers and food.
On 28Sept., at least 1 closed brood frame was seen in this colony. All the seven frames were at least covered with workers. At least 2 of the frames were drawn of combs around 1/3 inch from the wax foundation. 1 open brood frame and 2 food frames were introduced to this colony from our stronger colony. On this day, this colony had 10 frames.
The whole of October this colony had brood frames and all the frames have been covered by workers. Frequency of feeding of the quantity of sugar have been the same.
On the last visit and feeding last 15Nov., no more brood nor egg can be found on this colony. She was walking briskly around 1 of the frames. I saw a lot of empty drawn combs. There was no problem with cells to lay eggs in. I saw that there were no more mites. Once in a while, I saw very few ants, but they were insignificant in numbers.
There was no problem with the other 5 colonies. Eggs, open and closed brood were seen. They have been steadily increasing in strength.