Nosema

[Mellifera Crofter]

I discovered yesterday that a colony that swarmed into a bait hive while on the heather, have reduced to a handful of bees with a pile of dead ones on the floor, and are riddled with Nosema (I checked with a microscope). I'm a bit baffled, because the queen was laying well while on the heather, but back home, when I checked late September, I began to suspect that they were queenless. I don't know what happened to the queen. Could Nosema have killed her? I moved the handful of bees into a nuc - just in case there's a queen that's going to start laying, but I think it's too late. The colony is doomed.

I also wondered whether they might suffer from some other viral illness. Some bees have elongated, shiny abdomens - not really bloated, but extended, or long. I've added a picture of one such bee. I picked her up from the floor as part of a sample of dead bees, but she recovered before I started grinding up their abdomens. She is one such bee with a shiny, long abdomen. I've attached a photo - not a good one, I'm afraid.

Celia Davis mentions filamentous virus. I should have read up, and checked for white milky haemoglobin before grinding up the abdomens - but I can't remember having noticed it.

Kitta

3012

[Adam]

Kitta, I haven't a particular answer but a couple of questions; What happened to the swarmed hive - was it able to re-queen or did itself have any health/disease issues? And did the swarm queen actually lay in the bait hive? (I am thinking that an unhealthy colony is unlikely to swarm late in the year under 'normal' circumstances).

[Mellifera Crofter]

I don't know which hive the swarm came from, Adam. I took four colonies to the heather, and they took me by surprise: three of them made swarm preparations, and I did lose some in swarms. I also wondered whether the mother colony had Nosema, but as they all returned home healthy and very strong, I thought that they might have been able to suppress it, if they did have it.

The swarmed colony in the bait hive was doing fine whilst on the heather. The queen was laying and they were expanding. Back home I added Varroa strips and noticed no brood - but as it was already September I thought that's perhaps just a brood break. I got worried by the time I removed the Varroa strips, and then now I think they're queenless! I also saw an emerged queen cell! So, if there is a new queen in there, she probably didn't get mated. I don't think the original swarm queen swarmed away again - but who knows ...

[Adam]

Was it MAQS strips you used that might have caused supercedure? (I know this doesn't explain the reason for the thread but could explain why the queen has possibly gone).

[Mellifera Crofter]

No, I used Apivar, Adam. I think the problem started even before I added the strips, but by that time it was cold, and I didn't investigate closely. I just thought the queen was taking a break. Thanks for trying to help, Adam.

Come spring, I'll check the other heather colonies, one of which might have been the mother colony, for signs of trouble.
Kitta