Varroa destructor and viruses association in honey bee colonies under different climatic conditions

Abstract

Honey bee colonies are threatened by multiple factors including complex interactions between environmental and diseases such as parasitic mites and viruses. We compared the presence of honeybeepathogenic viruses and Varroa infestation rate in four apiaries: commercial colonies that received treatment against Varroa and non-treated colonies that did not received any treatment for the last 4 years located in temperate and subtropical climate. In addition, we evaluated the effect of climate and Varroa treatment on deformed wing virus (DWV) amounts. In both climates, DWV was the most prevalent virus, being the only present virus in subtropical colonies. Moreover, colonies from subtropical climate also showed reduced DWV amounts and lower Varroa infestation rates than colonies from temperate climate. Nevertheless, non-treated colonies in both climate conditions are able to survive several years. Environment appears as a key factor interacting with local bee populations and influencing colony survival beyond Varroa and virus presence.

Honey bee viruses in Serbian colonies of different strength

“…In this study, samples from clinically healthy colonies in Serbian apiaries were analysed by real-time RT-PCR in order to detect honey bee viruses (DWV, ABPV, SBV and CBPV) and determine their prevalence patterns and prevalence. The results revealed DWV to be the most prevalent virus in Serbian apiaries, not unlike in many other countries: Hungary ( Bakonyi et al, 2002 ), France ( Tentcheva et al, 2004 ; Mouret et al, 2013 ), Austria ( Berenyi et al, 2006 ), Slovenia ( Toplak et al, 2012 ) and Uruguay ( Giacobino et al, 2016 ). High prevalence of DWV (74%) and ABPV (49.3%) recorded in Serbian apiaries are not surprising, knowing their close relation to V. destructor mite infestation and their persistence as subclinical infection in apparently healthy colonies ( Gauthier et al, 2007 ; Mouret et al, 2013 ; Wells et al, 2016 ).…”

Peer Review #3 of "Honey bee viruses in Serbian colonies of different strength (v0.1)"

“…Among monitored honey bee viruses in Serbia, the highest incidence was recorded for DWV (66.7-83.3%). No significant differences in its prevalence among Serbian regions is not surprising knowing its global occurrence (Wilfert et al, 2016) and its dominance over other viruses in variable environmental conditions (Giacobino et al, 2016).…”

“…It can be assumed that these results may reflect the beekeepers' negligence of apicultural measures (Stanimirovic et al, 2007a), but also may have risen from different means of V. destructor control (Nielsen, Nicolaisen & Kryger, 2008) Manuscript to be reviewed which may be the reason only in ABPV infection, since not all viruses are transmitted by varroa mites (Glenny et al, 2017). Nevertheless, differences in orographic factors and forage quality between regions should be also considered as the environment was suggested as a key factor interacting with local bee populations and ecogenotypes Giacobino et al, 2016). Our results concerning 87.33% samples with at least one virus and 58.66% with two or more are similar to those observed in Austria (Berenyi et al, 2006), France (Tentcheva et al, 2004;Gauthier et al, 2007) and Slovenia (Toplak et al, 2012).…”

Beekeeping and honey bee colony health: A review and conceptualization of beekeeping management practices implemented in Europe

“…For instance, oxalic acid have an efficacy greater than 90% when applied during broodless period while the efficacy falls to 60% (or lower) for colonies containing brood (Rademacher and Harz, 2006;Rosenkranz et al, 2010;van der Zee et al, 2014). Shorter summers result in fewer mite reproduction cycles and thus a lower level of infestation (Giacobino et al, 2016). In Europe there are areas in which brood is reared during the whole year, while in others (e.g.…”