Had a very successful large early bumble bee colony in old bird nest box, could even see their honey store (don’t know technical term) through the opening. Latley been less bees (thought it was them dying off naturally) and no longer see their honey store. Just noticed today larger bees keep going into nest. They are not happy as keep trying to attack these invaders but they are much bigger and get inside the nest. Looked on internet and can’t see anything why this would happen, as can’t be cuckoo if they are trying to attack them can they??? any ideas I am so upset for them.
it could be B Sylvestris, a cuckoo bumblebee that attacks the nest of B Pratorum (Early BB) that you are seeing. Females searching for a ‘host’ can be seen anytime between April - June or sometimes even in to July.
Have you got a photo that you could post…... that would help to identify the invaders !
Thank you, I am trying to get photo but they are too quick. There seems to be more than 1 which is what concerned me that it couldn’t be a queen and also that their honey has gone but I will keep trying to identify them/get a photo.
As the nest seems to be occupied every year, is there anything I can do next year to stop this happening, it is a bird box on the side of my house so is very on display and open. Also I have another 2 bee nests at the back of my house (house seems to be a popular spot for some reason!) so was worried maybe its some sort of competition thing?
Thank you for your help.
The symptoms you have described could fit with the ‘drone cloud’ that occurs at B. hypnorum nests.
Take a look at the Tree Bumblebee thread and see if any of the comments there fit !
And by the way, blurred photos are often good enough for the sort of rough i/d purposes most of have.
(And pictures in flight of the bee activity outside the box too !)
I hope this helps.