I have a hive in France in the Dordogne. The bees have been suffering from a high mortality rate. ie there are a lot of dead bees on the floor and entrance. These are removed to avoid spreading the complaint.There are no verroa mites visible on the mesh floor insert.. They have been treated for acarine and nosema and have been inspected under a microscope with no apparent problems. If left out in the sun some of the bees appear to revive and some start flying again. My bee teacher suspects poisoning and although they have sprayed plum trees in the last 2 months it does seem to be going on a long time (ie a high mortality rate for the last 6 to 7 weeks. My current thought is the illegal use of treated oil seed rape seed (gaucho i think) which has been banned in France since last year.
Does anybody have any expeirience of these type of symptoms?. My current strategy is to feed with 1 to 1 sugar to try to boost the hive, keepi it going until any poisoned stores are used and any poisoned pollen finished.
Any other ideas?