Screening and identification of viruses in termites: behavior-regulating roles of RcBsV and RcBV

Termites live underground in a social setting having continuous contact with microorganism. However, there is no comparative study on virus diversity and relative abundance between termites, castes and body parts in termites. To address this gap, pseudergates of Cryptotermes declivis, workers of the Odontotermes formosanus, and workers, soldiers and alates of the Reticulitermes chinensis were used as experimental materials to perform virome sequencing, virus annotations and their relative abundance analysis.

It was found that three termites showed different virome taxonomic compositions, abundances and distributions. Small number of viruses were detected in the head, which indicated that the diversity of the virus in the thorax-abdomen is greater than that in the head. Notable differences in viruses between castes in R. chinensis were observed. Eight candidate viruses from the virome of R. chinensis were cloned and identified. To check the influences of viruses on termite behaviors, RNA interference of R. chinensis betsystermes virus (RcBsV) and R. chinensis bracovirus (RcBV) was successfully performed. The relative abundance of the two targeted viruses were significantly decreased in workers of R. chinensis fed on dsRcBsV and dsRcBV. The duration of aggressive behaviors significantly increased, while altruistic behaviors significantly decreased, suggesting that the reduced relative abundance of RcBsV and RcBV resulted in the disruption of normal social behaviors in termites.

These findings enhance our understanding of viral diversity in different termites and castes and its behavioral impacts on termites, which can be used to control termites. © 2024 Society of Chemical Industry.