Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2026
Publication Date: 1/31/2026
Citation: Valles, S.M., Zhao, C., Porter, S.D., Becnel, J.J. 2026. Isolation, Characterization, and Host Specificity of Solenopsis invicta Virus 6 (Cripavirus porteri), a Dicistrovirus from the Red Imported Fire Ant, Solenopsis invicta. Journal of Invertebrate Pathology. 216:108557. https://doi.org/10.1016/j.jip.2026.108557.
DOI: https://doi.org/10.1016/j.jip.2026.108557

Interpretive Summary: The red imported fire ant was introduced into the United States from South America nearly 100 years ago. It currently infests about 300 million acres and causes approximately $8 billion in damage annually. Biologically-based control is considered the most promising approach to managing the pest, providing cost-effective and sustainable control in the USA. An important group of biological control agents against the red imported fire ant is viruses, including the recent discovery, Cripavirus porteri. Studies were conducted by scientists in the Imported Fire Ant and Household Insects Research Unit (ARS), Gainesville, Florida, to determine the impact of Cripavirus porteri against the invasive fire ants in the USA and to assess its potential as a biological control agent this ant pest. The virus exhibits a broad host range beyond ants making its use against fire ants limited.

Technical Abstract: Solenopsis invicta virus 6 (SINV-6; Cripavirus porteri) is a recently discovered dicistrovirus from the red imported fire ant, Solenopsis invicta. SINV-6 was detected in all stages of S. invicta including eggs, pupae, larvae, adult workers, male and female sexual alates, and queens. When held in the laboratory, worker ants, larvae, and pupae maintained a SINV-6 infection. Electron microscopic examination of negatively stained samples from particles purified from SINV-6-infected fire ant workers revealed isometric particles with a mean diameter of 34.2 ±2.1 nm. Field surveys of S. invicta nests in Alachua County, Florida, showed that the virus was present year-round. SINV-6 prevalence ranged from 37.5% in February to 100% in November. Among 171 nests surveyed throughout the year and over the 6-year period, 106 (62%) tested positive for SINV-6. Intra-colonial SINV-6 infection rates and virus titer among worker ants exhibited a positive relationship. As intracolonial prevalence increased, a corresponding increase in the mean virus titer was observed. SINV-6 exhibited tissue tropism toward the abdomen where >99% of SINV-6 was detected. Among the major tissues of the abdomen, the alimentary canal (midgut, hindgut, crop) contained 87.6% of SINV-6. The midgut and hindgut contained the highest amount of virus (58.0 ±28.7%). Small quantities of SINV-6 were detected in fat body (8.4 ±0.4) and Malpighian tubules (4.0 ±0.4%). SINV-6 infection did not have an impact on brood production in S. invicta over a 26-day period when held in the lab compared with uninfected control colonies. The host range of SINV-6 was found to be broad with the plus strand of the virus’ genome detected six species of ants and the honeybee (Apis mellifera).