Discovery and molecular characterization of an ambisense densovirus from South American populations of Solenopsis invicta

- Metagenomics was employed to prospect for viral biocontrol agents of Solenopsis invicta.
- The first densovirus infecting a hymenopteran species was discovered.
- Solenopsis invicta densovirus is found exclusively in native populations.
- SiDNV is a potential classical biological control agent for S. invicta in the USA.

In an effort to discover viruses as classical biological control agents, a metatranscriptomics/pyrosequencing approach was used to survey native Solenopsis invicta collected exclusively in Argentina. A new virus was discovered with characteristics consistent with the family Parvoviridae, subfamily Densovirinae. The virus, tentatively named Solenopsis invicta densovirus (SiDNV), represents the first DNA virus discovered in ants (Formicidae) and the first densovirus in a hymenopteran insect. The ambisense genome was 5280 nucleotides in length and the termini possessed asymmetrically positioned inverted terminal repeats, formed hairpin loops, and had transcriptional regulatory elements including CAAT and TATA sites. Phylogenetic analysis revealed that SiDNV belongs to a group that includes two other densoviruses found in insects (Acheta domestica densovirus and Planococcus citri densovirus). SiDNV was prevalent in fire ants from Argentina but completely absent in fire ants found in the USA indicating that this virus has potential for biological control of introduced S. invicta.