Rose rosette was first described in the early 1940s and it has emerged as one of the most devastating diseases of roses. Although it has been 70 years since the disease description, the rosette agent is yet to be characterized. In this communication, we identify and characterize the putative causal agent of the disease, a negative-sense RNA virus and new member of the genus Emaravirus. The virus was detected in 84/84 rose rosette-affected plants collected from the eastern half of the USA, but not in any of 30 symptomless plants tested. The strong correlation between virus and disease is a good indication that the virus, provisionally named Rose rosette virus, is the causal agent of the disease. Diversity studies using two virus proteins, p3 and p4, demonstrated that the virus has low diversity between isolates as they share nucleotide identities ranging from 97 to 99%.

In March 2020, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. At the genus rank, 20 new genera were added, two were deleted, one was moved, and three were renamed. At the species rank, 160 species were added, four were deleted, ten were moved and renamed, and 30 species were renamed. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.

In 2018, the family Arenaviridae was expanded by inclusion of 1 new genus and 5 novel species. At the same time, the recently established order Bunyavirales was expanded by 3 species. This article presents the updated taxonomy of the family Arenaviridae and the order Bunyavirales as now accepted by the International Committee on Taxonomy of Viruses (ICTV) and summarizes additional taxonomic proposals that may affect the order in the near future.