Honey Bee Parasite, Varroa destructor!
Varroa destructor is an underestimated parasite: it is genetically labile, with multiple hybridization and dispersal events.
Varroa is also a highly efficient vector of honey bee viruses and drives changes in virus distribution, prevalence, and virulence. Despite this, some Apis mellifera populations can survive without human intervention on all continents where varroa has dispersed.
Scientists and specialist breeders are advancing marker-assisted selection techniques to enrich naturally occurring varroa-resistance traits in commercial stock – an approach predicted to be most effective when combined with culling susceptible colonies.
Culling is identified as an effective means of removing both undesirable genetics and varroa-related virulence.
https://www.cell.com/trends/parasitology/fulltext/S1471-4922(20)30101-X
