High prevalence of Varroa destructor in Apis mellifera colonies from the largest honey producing state in Brazil.

Varroa destructor is regarded as a major threat to beekeeping worldwide. However, there are no official reports of V. destructor occurrence or related damage in Rio Grande do Sul, the largest honey producing state of Brazil. The present study aims to estimate the prevalence of V. destructor, identify its potential risk factors and perform spatial analysis according to the level of infestation of the colonies. A total of 1302 samples of adult honey bees from hives across 375 farms were analyzed. The overall prevalence of Varroa destructor was 95,16 %. The study revealed two risk factors for high infestation rate of V. destructor: scale of beekeeping and biome. Spatial analysis revealed that regions with the highest rates of mite infestation overlap with areas of the greatest apiary concentration. This study emphasizes the need to adopt minimum management practices to maintain strong and healthy colonies.