Data from: Variable viral loads and immune response in tan invasive ant’s native and introduced ranges

Aim: Pathogens can play an important role in biological invasions.
Introduced populations may be particularly vulnerable to pathogens due to
factors such as low genetic diversity and high population density.
However, introduced populations that escape their natural pathogens may
reallocate resources away from immunity and towards growth and
reproduction. Interestingly, introduced ants have been suggested to have
increased tolerance to new pathogens, contributing to their success as
introduced species. In this study, we aimed to investigate whether
introduced Argentine ant populations harbour different viral loads
compared to native populations and if these differences were related to
immunity-related gene expression. Location: The study was conducted across
the native range of Argentine ants in Argentina and four introduced
regions in California, France, Australia, and New Zealand. Methods: We
used RT-qPCR to quantify viral loads and gene expression in the ants. We
analysed 15 different potentially pathogenic viruses across the Argentine
ant’s native and introduced ranges. Results: We found that five viruses,
LhuPcV1, LhuPiLV1, LhuCV1, Kashmir Bee virus, and LHUV-1, presented high
loads in Argentine ants compared to the other viruses we screened. We
found a significant effect of range on viral infections: high viral loads
were commonly found in ants from introduced populations, which also
exhibited increased immune gene expression. We found highly significant
correlations between viral loads and expression of immune and metabolic
genes. However, these associations were not fully consistent across the
studied regions, indicating the complexity of eco-immunological phenomena.
Main conclusions: Our results suggest that introduced Argentine ant
populations host different viral communities compared to native
populations and that these differences are correlated with changes in
immunity-related gene expression. The study highlights the complex role of
pathogens in biological invasions and the importance of considering
eco-immunological factors when assessing the impact of introduced species.