The First Draft Genome of a Brood Parasitic Bee, Holcopasites calliopsidis

While bees are often associated with the evolution of eusociality, this system is actually present in fewer than 10% of bee species. This bias is also represented in literature, including the field of genomics - two-thirds of the approximately fifty bee species with published genomes are eusocial. When compared to eusociality, brood parasitism, with over 2,500 representatives across the phylogeny of bees, is a more common but far less well-known phenomenon. These “cuckoo bees”, like the birds from which their colloquial name is derived, are obligate parasites of other species, laying their eggs in a host bee’s nest and allowing their offspring to consume the food provisions within. We here present the first genome of a brood parasitic bee, Holcopasites calliopsidis, a parasite of mining bees in the genus Calliopsis. This high-quality assembly was generated from a single individual using Pacific Biosciences sequence data and annotated for comparison with previously published genomes of non-parasitic bees. Though further work is needed, preliminary findings indicate several interesting genomic features that differ from other bees and may be associated with the various unique adaptations associated with brood parasitism.