Honey bee (Apis mellifera L.) tolerance to Varroa jacobsoni Oud. in South America

The study of Apis mellifera colonies in South America that are tolerant to Varroa jacobsoni may help us to understand the general requirements for V. jacobsoni tolerance. The situations in Brazil, Uruguay and Argentina are described. There are clearly different modes and levels of V. jacobsoni tolerance in these countries. The Africanized honey bee in tropical Brazil has extremely low infestation rates, and reduced V. jacobsoni fertility in worker brood is a striking tolerance factor. In Uruguay, long-term survival of untreated and presumably non-Africanized honey bee colonies was confirmed. Striking tolerance factors, however, were not evident in Uruguay and infestation levels are higher than in Brazil. In the non-tropical regions of Argentina honey bee colonies cannot survive without V. jacobsoni treatment. The actual data cannot answer the question whether the observed V. jacobsoni tolerance is a trait of the host or is due to lower virulence of the parasite. The ecological conditions which may have favoured natural selection in Brazil and Uruguay are discussed. (C) Inra/DIB/AGIB/Elsevier, Paris.