Robbing
Krankheiten
Robbing refers to bees raiding foreign colonies to steal their stores.
Robbing refers to bees raiding foreign colonies to steal their stores. It occurs mainly during nectar dearths, typically in high summer and in late summer after the last harvest, when nothing is blooming anymore but the colonies are still strong. It is usually triggered by beekeeping practice itself: spilled feed syrup, open honey combs, hives left open for a long time, open feeding at the apiary, or weak units with an entrance far too large.
The signs are unmistakable. Bees fight each other at the entrance, robber bees run searchingly over the hive and probe cracks and gaps instead of flying in purposefully. Flight activity looks hectic and undirected, dead bees lie in front of the hive, and inside one finds torn, glistening, and ragged comb edges from which the honey has been torn out. A raided colony loses all its stores and often the queen as well.
Robbing is especially dangerous as a disease spreader. Foulbrood pathogens, Nosema spores, and viruses are carried into other colonies along with the stolen honey, and the mites of collapsing colonies spread across the whole apiary during robbing. A sudden rise in mite drop in neighboring colonies often has exactly this cause.
In cases of acute robbing, the entrance of the raided colony is immediately narrowed to bee width, feeding is stopped, and the hive is sealed against access through cracks. It has also proven effective to lay a wet cloth over the hive, which slows down approaching robber bees. Very weak or already robbed-out colonies are better dissolved or united with a strong colony rather than continuing to expose them to plundering.
As prevention: feed only in the evening and only in closed feeders, do not leave feed residue lying at the apiary, never leave combs and honey standing open, work quickly and do not keep colonies open unnecessarily long, adjust entrances to colony strength, and keep nuclei at a different location where possible. Anyone who eliminates the causes does not need to fight the symptoms.