Dynamics of israeli acute paralysis virus in red imported fire ant(solenopsis invicta buren) colonies

Authors: VALIZADEH GEVER, BITA - Mississippi State University; HARDY, JULIE - Mississippi State University; Chen, Jian; AMIRI, ESMAEIL - Mississippi State University

Submitted to: Journal of Invertebrate Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2025
Publication Date: 3/7/2025
Citation: Valizadeh Gever, B., Hardy, J., Chen, J., Amiri, E. 2025. Dynamics of israeli acute paralysis virus in red imported fire ant(solenopsis invicta buren) colonies. Journal of Invertebrate Pathology. 211(2025) 108310.

Interpretive Summary: Israeli acute paralysis virus (IAPV) is a widespread RNA virus of honey bees and has been associated with colony losses. The red imported fire ant, one of the most significant pest ants in the southern United States, is frequently found in honey bee colonies and their surrounding areas. Fire ants consume dead bees, and their potential role as secondary hosts or reservoirs has been studied for many honey bee-associated viruses. However, the viral dynamics and persistence within fire ant colonies remain poorly understood. In this study, a series of experiments was conducted to test the possibility of IAPV transmission from honey bee to fire ant colonies, as well as horizontal and vertical transmission and virus persistence within fire ant colonies. The results showed that fire ants can acquire IAPV by consuming virus-infected honey bees, and the virus can spread rapidly within the colony. It is transmitted horizontally among worker ants, infecting all developmental stages, including larvae, pupae, and adults. The virus can also be transmitted to queens and subsequently passed vertically from infected queens to their eggs. Virus circulation within colonies was monitored over four months, and a significant viral load persisted in all developmental stages of colony members during this period. These findings suggest that fire ants can act as virus reservoirs, posing a potential threat to the declining health of bee pollinators.

Technical Abstract: The red imported fire ant, Solenopsis invicta Buren, is one of the most significant pest ants in the southern United States, frequently found in honey bee colonies and their surrounding areas. While fire ants scavenge on dead bees and may function as secondary hosts or reservoirs for several honey bee-associated viruses, evidence of viral dynamics and persistence in fire ant colonies has been inconclusive. In this study, we conducted a series of experiments to test the possibility of food-borne virus transmission i.e. horizontal transmission from virus[1]infected honey bee pupae to fire ants and persistence of the virus within the fire ants’ colonies. Israeli acute paralysis virus (IAPV) was used as an experimental pathogen due to its relevance to honey bee health and its limited prevalence. Our results showed that fire ants can acquire IAPV horizontally by consuming virus-infected honey bees. The virus may spread rapidly across all developmental stages (larvae, pupae, and workers) within the colony, likely facilitated by the social interactions. Additionally, fire ant queens can likely acquire the virus via trophallaxis and/or physical contact with workers. Our results further indicated that IAPV could be transmitted vertically, however confirmatory research is required. Monitoring the virus after 4 months of inoculation confirmed that a significant IAPV load persists in all developmental stages of colony members. These findings suggest that fire ants can act as virus reservoirs for a deadly honey bee-associated virus, posing a potential threat to the health and well-being of bee pollinators.