Honey bees and climate explain viral prevalence in wild bee communities on a continental scale

Abstract

Viruses are omnipresent, yet the knowledge on drivers of viral prevalence in wild host populations is often limited. Biotic factors, such as sympatric managed host species, as well as abiotic factors, such as climatic variables, are likely to impact viral prevalence. Managed and wild bees, which harbor several multi-host viruses with a mostly fecal–oral between-species transmission route, provide an excellent system with which to test for the impact of biotic and abiotic factors on viral prevalence in wild host populations. Here we show on a continental scale that the prevalence of three broad host viruses: the AKI-complex (Acute bee paralysis virus, Kashmir bee virus and Israeli acute paralysis virus), Deformed wing virus, and Slow bee paralysis virus in wild bee populations (bumble bees and solitary bees) is positively related to viral prevalence of sympatric honey bees as well as being impacted by climatic variables. The former highlights the need for good beekeeping practices, including Varroa destructor management to reduce honey bee viral infection and hive placement. Furthermore, we found that viral prevalence in wild bees is at its lowest at the extreme ends of both temperature and precipitation ranges. Under predicted climate change, the frequency of extremes in precipitation and temperature will continue to increase and may hence impact viral prevalence in wild bee communities.

“Migratory beekeeping and its influence on the prevalence and dispersal of pathogens to managed and wild bees”

“…Several studies have also highlighted the important role that climatic variables play in disease prevalence and risk in honey bees ( Giacobino et al, 2017 ; Rowland et al, 2021 ). At a continental scale, however, no relationship has been found between honey bees and viral prevalence, probably due to features of their social life that allow them to regulate hive temperature or maintain food resources in good condition ( Piot et al, 2022 ). However, this study has found a correlation between viral prevalence and climatic variables in wild bees that could impact honey bees by spillback.…”

“…Furthermore, there are no specific studies assessing the role of migratory beekeeping on the spread of pathogens and parasites across wild bee communities which results astonishing given the current worldwide decline of bees. Due to increasing evidence of pathogen transmission from managed to wild bees ( Manley et al, 2019 ; Martinez-López et al, 2021 ; Nanetti et al, 2021 ; Piot et al, 2022 ), there is an urgent need for future studies to assess the impact of migratory beekeeping on wild bees. For this, studies with appropriate experimental designs with a control area free of managed honey bees, and taking into account all the above mentioned factors are needed.…”

“…While pathogens and diseases are mainly threatening managed European honey bees ( Steinhauer et al, 2018 ), the decrease in wild bees, among other flying insects, seems to be especially driven by land-use change and agricultural intensification ( Hallmann et al, 2017 ; Raven and Wagner, 2021 ). In any case, recent studies have demonstrated the transmission of pathogens from honey bees to wild bees and vice versa (known as pathogen spillover and spillback, respectively) ( Martinez-López et al, 2021 ; Nanetti et al, 2021 ; Piot et al, 2022 ). This spillover is partly mediated by the presence of infected honey bees in different habitats (González-Varo et al, 2017; Manley et al, 2019 ), which can deposit pathogens on flowers and thus cause them to act as vectors for pathogen transmission between different pollinator species ( Singh et al, 2010 ; Graystock et al, 2015 , 2020 ).…”

Increasing flower species richness in agricultural landscapes alters insect pollinator networks: Implications for bee health and competition

“…We also calculated two network metrics: connectance, a measure of interaction diversity within networks and a relevant index to predict disease transmission between bees (Figueroa et al, 2020), and bees' niche overlap, a measure of resource sharing and a proxy for competition between taxa (Taggar et al, 2021). We focused our study on honeybees and bumblebees, two common and important crop pollinator taxa with a strong potential for competitive interactions (Goulson & Sparrow, 2009; Wignall et al, 2020) and disease transmission (Fürst et al, 2014; Manley et al, 2019; Piot et al, 2022).…”

Reduced parasite burden in feral honeybee colonies

“…If feral colonies carry high loads of parasites, however, they might reinfect managed colonies, thereby undermining the veterinary measures undertaken to combat disease [29,32]. When highly infected feral colonies disperse into natural areas, their parasites might also spill over to, and harm, populations of other (wild) bee species [33][34][35].…”