Bee Health in Apiaries in the Paraíba Valley, São Paulo State, Southeast Brazil

Bee health is a growing global concern due to phenomena with as yet undefined causes, such as the sudden population decline of colonies that has been observed in apiaries in many countries, recently including Brazil. The main objective of this study was to assess the presence and/or prevalence of pathogens that afflict Africanized Apis mellifera bees in the Paraíba Valley region of São Paulo state, Brazil. Three sampling periods were established: period 1 – August and September 2009 (winter/start of spring); period 2 – December 2009 and January 2010 (summer); and period 3 – April and May 2010 (autumn). Different types of samples were collected from the brood chamber, besides foragers at the entrance of the hive, in order to evaluate the presence and prevalence of Paenibacillus larvae, Varroa destructor and Nosema sp. The results indicated that the intensity of infection by Nosema ceranae and infestation rates of V. destructor in the hives are low, with no detection of P. larvae spores in the samples analyzed. The prevalence of N. ceranae and V. destructor was high, at respective values of 85.2 and 95.7%. These results demonstrate that although mites and microsporidia are widespread in the region’s colonies, the Africanized bees are apparently tolerant of these parasites. However, the mechanisms related to defense against pathogens are not completely clear and monitoring and prophylactic measures are essential to maintain the health of bee colonies