Effect of oral infection with Kashmir bee virus and Israeli acute paralysis virus on bumblebee (Bombus terrestris) reproductive success

Abstract

Access to the published version may require journal subscription. Published with permission from: Elsevier. was established by analysis of the bumblebees after the impact studies: 50 days after 32 infection. Doses of 0.5 x 10 7 and 1 x 10 7 virus particles per bee were infectious over 33 this period, for IAPV and KBV respectively, while a dose of 0.5 x 10 6 IAPV particles 34 per bee was not infectious. The impact of virus infection was studied in micro-35 colonies consisting of 5 bumblebees, one of which becomes a pseudo-queen which 36 proceeds to lay unfertilized (drone) eggs. The impact parameters studied were: the 37 establishment of a laying pseudo-queen, the timing of egg-laying, the number of 38 drones produced, the weight of these drones and worker mortality. In this setup KBV 39 infection resulted in a significant slower colony startup and offspring production, 40 while only the latter can be reported for IAPV. Neither virus increased worker 41 mortality, at the oral doses used. We recommend further studies on how these viruses 42 transmit between different pollinator species. It is also vital to understand how viral 43 prevalence can affect wild bee populations because disturbance of the natural host-44 virus association may deteriorate the already critically endangered status of many 45 bumblebee species. Introduction 51The Apoidea, encompassing different families of bees, perform a valuable pollination 52 service (Garibaldi et al., 2013). With up to 80% of the plant species being dependent 53 on insect pollination, in particular by bees (Potts et al., 2010). This results in an 54 estimated value of 9.5% of the total economic value of crops that are directly used for 55 human food (Gallai et al., 2009; Potts et al., 2010). Because of a lack of 56 abundance/presence of wild bees, managed bees are used to pollinate crops (Allsopp 57 et al., 2008). 58Because different bee species have a similar foraging behavior (gathering pollen and 59 nectar), with overlapping flower networks, sympatric distributions and direct 60 interactions between species or their stored resources, it is very likely that they are 61 exposed to each other's parasites and pathogens. Indeed, parasite networks between 62 bee species are complex and comprise a mixture of multi-host parasites (e.g. Apicystis 63bombi (Maharramov et al., 2013), Nosema ceranae (Graystock et al., 2013a), 64 deformed wing virus (DWV) (Fürst et al., 2014)), as well as multi-parasite hosts 65 (Rigaud et al., 2010). However, with the exception of honeybees (Apis spp.), little is 66 known about the parasites and pathogens of pollinators, even less about the extent to 67 which they cross-infect different pollinators, and almost nothing about the damage of 68 such cross-infections to different hosts. 69Here we focus on the effects of interspecific transmission of bee viruses. Most of 70what is known about bee viruses relates to the European honeybee (Apis mellifera) 71 and its sister species (primarily the Asian hive bee; A. cerana), largely through the 72 pione...

A sting in the spit: widespread cross‐infection of multipleRNAviruses across wild and managed bees

“…Meeus et al . 2014), and to test competing hypotheses for host species differences in disease prevalence.…”

Israeli acute paralysis virus associated paralysis symptoms, viral tissue distribution and Dicer-2 induction in bumblebee workers (Bombus terrestris)

“…Orally delivered IAPV also increased mortality in adults, but a much higher starting dose was needed (Piot et al, 2015). Low oral viral doses did not induce mortality but had effects on reproduction of bumblebees (Meeus et al, 2014). Aside from the above mortality and sub-lethal effects, the symptoms associated with IAPV have not been well characterized and thus hinder our ability to observe the progression of IAPV infection in these important pollinators, especially when considering that virus-induced paralysis symptoms are normally the signal of overt infection and death.…”

“…a subset of honeybee-infecting viruses has been reported, such as deformed wing virus (DWV), Israeli acute paralysis virus (IAPV), acute bee paralysis virus (ABPV), Kashmir bee virus (KBV), slow bee paralysis virus (SBPV), sacbrood virus (SBV), black queen cell virus (BQCV) and Lake Sinai virus (LSV) (Genersch et al, 2006;Levitt et al, 2013;Parmentier et al, 2016;Peng et al, 2011). However, only DWV, KBV and IAPV have been reported to cause clinical symptoms (Genersch et al, 2006;Meeus et al, 2014). DWV caused crippled wings in bumblebee (Bombus terrestris and Bombus pascuorum) workers even without Varroa (Fürst et al, 2014;Genersch et al, 2006).…”

Honey Bee Viruses in Wild Bees: Viral Prevalence, Loads, and Experimental Inoculation

“…Singh et al [25] detected black queen cell virus (BQCV), DWV, Israeli acute paralysis virus (IAPV), Kashmir bee virus (KBV), and sacbrood virus (SBV) in multiple bee and wasp species. Most notably, many honey bee viruses have been routinely detected in bumble bees [18, 25–27] where they cause detrimental effects on development, lifespan, and colony health [28–30]. Spread of these viruses to bumble bees likely occurs from direct or indirect contact with infected honey bees.…”