Data from: Resident viruses, but not honeybee-associated viruses, impair solitary bee fitness in the field

Viruses can impact individual host fitness and host population dynamics,
especially following viral host shifts. The decline of bee populations
over the last decades may be linked to viruses spilling over from
honeybees. However, evidence for the impact of spillover or resident
viruses on solitary bee fitness remains scarce. Here, by assessing
solitary bee (Osmia cornuta) foraging, offspring sex ratio, survival, and
body mass across seven locations in northern Switzerland, we show that
resident viruses – but not honeybee-associated viruses –impact tokens of
fitness in the field. Viral loads of Osmia-resident Ganda bee virus (GABV)
and Scaldis River bee virus (SRBV), honeybee-associated viruses (black
queen cell virus (BQCV) and deformed wing virus B (DWV-B) were quantified
in foraging females. Prevalence and loads of GABV and SRBV were higher
than BQCV and DWV-B. Further, females with high SRBV or GABV loads had
reduced offspring survival or lower male offspring body mass,
respectively, while honeybee-associated viruses had no impact on tokens of
O. cornuta fitness. We demonstrate that viruses can negatively affect
solitary bee fitness, but the degree of impact seems to vary with viral
type. This calls for further research to unravel the dynamics of
multi-host pathogens in pollinator communities.