COLOSS Virus Task Force: A Journey to the Dark Side of Honey Bee Health

Introduction Viruses significantly contribute to losses of western honey bee, Apis mellifera, colonies (Berthoud et al., 2010; Carreck et al., 2010). The incorporation of high throughput sequencing methods to investigate the presence of DNA and RNA viruses in honey bee colonies has led to the detection of a significant number of new viruses, as well as a deeper insight of the presence of variants of known viruses (McMenamin & Flenniken, 2018). This includes recently described viruses such as Moku virus (Mordecai et al., 2016), Apis Nora virus (ANV), Apis bunya virus-1,2 (ABV-1, ABV-2), Apis dicistrovirus (ADV), Apis flavivirus (AFV) (Remnant et al., 2017), Apis mellifera filamentous virus (AmFV) (Gauthier et al., 2015), Apis rhabdovirus-1,2 (ARV-1,-2)/Bee rhabdovirus-1,2 (BRV-1,-2) (Levin et al., 2017; Remnant et al., 2017), new viruses from the families Iflaviridae, Tymoviridae, Nudiviridae, and Parvoviridae (Gebremedhn et al., 2020; Schoonvaere et al., 2018), new Tymo-, Seco-, Partiti-, Noda-, Dicistro-, Circo-, Nege-, Sobemo-, and Toti-like viruses (Galbraith et al., 2018; Schoonvaere et al., 2018), and the many picorna-like viruses identified in Australian honey bees (Roberts et al., 2018).