Submitted to: Virus Genes
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/14/2019
Publication Date: N/A
Interpretive Summary: The red imported fire ant was introduced into the United States in the 1930s and currently infests about 300 million acres. It is estimated to cause $6 billion in annual economic losses to livestock and agricultural production and poses a serious threat to human health. Biological control is widely considered the most sustainable method of controlling the fire ant over its entire range. Viruses can plan an important role in providing sustainable and natural control of fire ants in the U.S. Scientists at the USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, utilized the metagenomics method to discover new viral natural enemies of this ant in Argentina for potential release in the U.S. as control agents. Nine new RNA viruses were discovered by this method providing unique research leads for future studies as natural control agents against these ants.
Technical Abstract: Nine new virus genomes were sequenced from the invasive fire ant Solenopsis invicta using metagenomic RNA sequencing. The virus sequences came from S. invicta workers, larvae, pupae, and dead workers taken from midden piles collected from across the ant’s native range in Formosa, Argentina. One of the virus genomes (Solenopsis invicta virus 6) was also detected in populations of North American S. invicta. Phylogenetic analysis of the RNA dependent RNA polymerase, the entire nonstructural polyprotein, and genome characteristics were used to tentatively taxonomically place these new virus genome sequences; these include four new species of Dicistroviridae, one Polycipiviridae, one Iflaviridae, one Totiviridae, and two genome sequences that were too divergent to be placed with certainty taxonomically. The S. invicta virome is the best characterized from any ant species and includes thirteen positive-sense, single-stranded RNA viruses (Solenopsis invicta virus 1 to Solenopsis invicta virus 13), double-stranded RNA virus (Solenopsis midden virus), and one double-stranded DNA virus (Solenopsis invicta densovirus). These new additions to the S. invicta virome offer potentially new classical biological control agents for S. invicta.