A comparison of the hygienic response of Africanized and European (Apis mellifera carnica) honey bees to Varroa-infested brood in tropical Brazil

In order to examine the significance of hygienic behavior for the tolerance to varroosis of Africanized honey bees, they were compared with non-tolera nt Carniolans in tropical Brazil. Capped worker brood cells were artificial ly infested with living Varroa mites, and inspected some days later. Uncapp ing, disappearance of the introduced mite and removal of the pupa were reco rded in a total of manipulated 3,096 cells during three summer seasons. The hygienic response varied between Africanized and Carniolan colonies, but t his difference was significant only in one year, during which Africanized h oney bees removed a significantly greater proportion of Varroa mites than E uropean honey bees. A high proportion of the mites disappeared from artific ially infested brood cells without damage to the pupae. The opening of the cell and the removal of the bee brood are independent traits of a graded re sponse by adult workers towards mite-infested brood cells. We found a highe r between-colony variation in the reaction towards Varroa-infested brood of Africanized honey bees compared to Carniolans. The overall similar respons e of the two bee types indicates that hygienic behavior is not a key factor in the tolerance to varroosis of Africanized bees in Brazil.