Infection with the multi-host micro-parasite Apicystis bombi (Apicomplexa: Neogregarinorida) decreases survival of the solitary bee Osmia bicornis.

The micro-parasites present in the Apidae pollinator community are mostly multi-host pathogens. To study the impact of these multi-host pathogens on the Apidae pollinator community, as a driver of wild bee decline, pathological studies are needed for different hosts. Yet data on the pathogenesis of these pathogens for different genera and species is scarce or lacking, especially for solitary bee species. In this study, we monitored the effect of the multi-host micro-parasite Apicystis bombi on the lifespan of Osmia bicornis, a common solitary bee. Our results show that A. bombi infection significantly reduces O. bicornis survival.