Honey bee health and losses in Brazil

Abstract

Brazil, though the Africanized honeybees are considered resistant and tolerant to most of bee pathogens and parasites, in recent years considerable losses have been reported in some localities, especially in the Southeast and Southern states. Since the phenomenon that is affecting honeybees around the world has been observed also in Brazil (with less intensity), we proposed a research project aiming to determine possible causes for such decline or losses, and in particular to test the likelihoods of specific predicted causative agent(s) for this condition. Alternative approaches, including genetic screening can be extremely useful and can accelerate important discoveries related to the current problem. Here it was present an overview about these activitites and a summary (2009 to 2011) of the situation in the two regions. No symptoms of the American Foul Brood were detected and analysis of more than 600 honey samples presented negative results, using the Brazilian official method for microbiological detection of Paenibacilus larvae in honey (molecular techniques confirmed such absence). Leptomonas apis, and Spiroplasma apis were also detected in São Paulo State samples. One of the main sanitary problems of the Africanized bees (beekeeper loses, sometimes, all colonies during less than one-month period) is Brazilian Sacbrood-like disease, caused by the toxic effects of the Stryphnodendron spp pollen in the Atlantic Forest and Savannah regions (Sac Brood Virus has not been detected in these colonies and the symptoms are similar). Nowadays, the selection for resistance is under evaluation. Other brood mortality has been also observed during the last years showing anomalous symptoms. In adult bees different type of viruses such as ABPV, DWV, BQCV, IAPV have been detected, and previously CWV, FV and CBPV. Accidents with insecticides have been related. Collapse and mortality of adult bees have been detected in sugar cane areas where neonicotinoids normally are used, but in areas without sugar cane crop too. Nosema ceranae is present in many apiaries, showing high prevalence. The obtained results indicated that N. ceranae infection seems to supress bees immune response of A.mellifera due the peptides transciptiom of the antimicrobes abaecina and himenoptaecina. N. apis was detected only in some localities of Santa Catarina and Paraná. Varroa destructor is present throughout apiaries, but causing no apparent direct economical damages. Replacement of the queens from beehives showing symptoms has been recommended, avoiding chemotherapeutic drugs usage. There is a critical need to increase the number of technicians and laboratories dedicated to bee pathology in several regions of the country in order to have a better control of the sanitary situation in the apiaries. Pathological, epidemiological, and widespread studies must be conducted as no single pathogen seems to be predominant in declining bee colonies.