RNA viruses of the odorous house ant, Tapinoma sessile

The odorous house ant, Tapinoma sessile, is a widespread native pest across North America. While commercial baits are a primary management method against this ant, potential viral pathogens and their interactions with the ant host are not clearly understood. In this study, we aim to characterize novel viruses in T. sessile, determine if they actively infect the ant host, and examine how the ant’s social organization shapes viral infection patterns. We generated a metatranscriptomic database for T. sessile colonies and identified four potential novel viruses, tentatively named viruses 5288, 1762, 31166, and 28715, which our phylogenetic analysis indicated belong to virus families Rhabdoviridae, Picornaviridae, Dicistroviridae, and Polycipiviridae, respectively. Artificial inoculation of uninfected colonies by feeding viral homogenates of viruses 1762 and 31166 resulted in active infection, suggesting these viruses can be horizontally transmitted via trophallaxis. The presence of these novel viruses and a virus determined to be ALPV were confirmed in different geographical populations of T. sessile and appear more prevalent in urban populations (polygyne, unicolonial) than their natural conspecifics (monogyne, colonial). The presence of three common honey bee viruses, DWV, KBV, and SBV, was also confirmed in the T. sessile colonies, and their prevalence levels tend to be higher in colonies collected in close proximity to beehives. Our findings provide important insights into interactions between viruses and the host’s social organization as well as virus spillover from honey bees, and represent a first step in the exploration of potential viral impacts on control strategies for this pest ant.