Insects are the most abundant and diverse group of animals on earth, but our knowledge of their viruses is biased toward insect-borne viruses that cause disease in plants, animals, or humans. Recent metagenomic studies and systematic surveys of viruses in wild-caught insects have identified an unanticipated large repertoire of novel viruses and viral sequences. These include new members of existing clades, new clades, and even entirely new virus families. These studies greatly expand the known virosphere in insects, provide opportunities to study virus-host interactions, and generate new insights into virus evolution. In this chapter, we discuss the methods used to identify novel viruses in insects and highlight some notable surprises arising from these studies.
Keywords: Arbovirus; Insect virus; Metagenomics; RNA interference; Small interfering RNA; Transcriptomics.