Brazil produced 64,188,949 kg of honey in 2023 and has 101,797 agricultural establishments with honey beekeeping activities (IBGE 2017). Of these, 65.28% (66,483) belong to the southern region of the country, which traditionally concentrates most of this activity. Among the states in the south, Rio Grande do Sul state (RS) has the most beekeepers, with 37,189 beekeeping establishments, representing 36.53% of the country's total and leads the country’s production of honey, achieving 9,111,304 kg in 2023 (IBGE 2017). Data from the Brazilian Association of Honey Exporters (ABEMEL 2022) show that honey exports almost doubled from 2016 to 2020, with 45,625 tons of honey exported in 2020. These trends point to a growing increase in the production and export of honey, which is highly valued in the international market because it is considered organic, positioning Brazil as one of the countries with the greatest global presence in the export of this product.

Various disease-causing agents affect honey bee health worldwide, resulting in economic losses due to reduced honey production and other products, or in extreme cases, the death of colonies. One of the main threats currently known is the Varroa destructor mite (Genersch 2010). According to Le Conte et al. (2007), in France, untreated and feral honey bee colonies mostly vanished a few years after V. destructor was found in the country in 1982. The V. destructor mite originated in Asia, where it was restricted to Apis cerana honey bees, without causing major damage. When Apis mellifera was introduced to Asia in the 20th century, it proved to be a highly susceptible host to the parasite, to which it was not adapted. Today, the mite is distributed all over the world and is considered a major threat to beekeeping (Traynor et al., 2020, Zemene et al., 2015). In Brazil, it entered São Paulo state in 1972, through the importation of infested queens from Paraguay that originated in Japan (De Jong, Morse, and Eickwort 1982) and has since spread throughout the country. In addition to feeding on honey bee fat body (Ramsey et al. 2019), the mite can transmit viruses that affect honey bees, such as Acute Bee Paralysis Virus (ABPV), Kashmir Bee Virus (KBV), Deformed Wing Virus (DWV) and others (Yañez et al. 2020).

Polyhybrids called Africanized honey bees (AHB) emerged in Brazil in the 1950s when African honey bees (Apis mellifera scutellata), introduced to increase honey productivity, escaped and interbred with European bee subspecies (Kerr 1967). Currently, AHB is the predominant population of honey bees in Brazil, as most Brazilian beekeepers acquire honey bee colonies by trapping feral bees using bait hives (De Jong 1996). The long-term tolerance to V. destructor displayed by AHB in Brazil is a multifaceted phenomenon, with the primary factor driving AHB's resistance being the reduced fertility of V. destructor females in worker brood. This is further supported by additional factors such as enhanced grooming and hygienic behavior of the AHB (Rosenkranz 1999). Furthermore, the feral honey bee population is consistently under selection pressure from the mite. The absence of mite treatments in Brazil could result in a continuous influx of heritable traits from the feral population, thereby accelerating the selection process for mite resistance (Rosenkranz 1999).

The detection of the V. destructor mite is a mandatory monthly notification to the Official Veterinary Service (OVS) (BRASIL 2013). Despite this obligation, there is no notification of occurrences of infestations by V. destructor in the official records of the Secretaria de Agricultura, Pecuária, Produção Sustentável e Irrigação (SEAPI) of the RS state, which shows that it is a disease neglected by Brazilian beekeepers. Castilhos et al. (2023) evaluated V. destructor infestation levels in Brazil using data from 361 samples analyzed in 71 studies conducted between 1977 and 2020, of which only 2 were from RS, highlighting the lack of scientific research on the epidemiology of V. destructor in this state. Also, the prevalence and risk factors for the mite in the RS state are unknown. This lack of attention to disease control can result in a rapid spread of the mite infesting a large number of apiaries and their hives, affecting the production of honey and other products, as well as pollination services. Therefore, the present study aims to estimate the prevalence of V. destructor, its spatial distribution and identify potential risk factors for high infestation levels in the A. mellifera apiaries of main honey producer state of Brazil.