I'm worried.

This is no change from the usuall but, I'm worried about the Russian colony. I went over to check on it today and they were very aggressive. The population had certainly increased but, my Italian colony was 3 times that size before their increased aggressian became noticable. I inspected the colony as usuall but, after opening it I decided to go with gloves. They were NOT happy. I pulled out a frame and they had completely drawn the comb but, it was empty; no brood and no honey. I continued searching all the frames and some had honey but, none had larval brood or eggs. The bees had a very loud buzz but it all sounded the same. Then, I picked up a frame, they buzzed as usuall but, just after I turned it over to inspect the other side I heard a loud sound, "Beeeeeeeeeeeeeeeee". This repeated a few times and I was slighly dumbfounded. I had never heard bees say their name. I've heard that this was the reason they are called bees but, never heard it myself. I was thinking at the time that possibly the broodless state was due to a lack of resources so, I put on a quart of 1:1 sugar syrup. I still have no idea why the only brood is capped. Some was emerging when I arrived but, I have come to a few likely conclutions. I saw some bees coming in with pollen and there was also a fair bit stored so I don't think their is a pollen dearth but, a lack of nectar. Their honey stores have been deeply tapped and I think the lack of brood has been caused by a lack of food. I do have some facts to back this up. Russians are more efficient in their brood rearing activeties and if the temperature is too cold to keep the brood warm or they don't have enough resources, they will stop brood production. Italians will maintain a large amount of brood until it gets too cold to cover it and keep it warm. Another idea as to why they are so short on brood is that their queen is dead, either by supersedure or my manipulations and inspections. This is very unlikely but, if it is the case, it's too late to buy a new queen and too late for the bees to raise their own so, I'd have to combine them with the Italian colony here. I really hope that isn't the case. If it does turn out to be a lack of nectar then, that is easily manageable. I'll be able to tell by how fast they drink the sugar syrup. I'll probably continue feeding them even if that isn't the problem just because they need to draw out comb and they need winter stores. I'll be checking up on them daily or at least every other day to see what the situation is. I hope they're alright.