Phasmavirus-derived genome sequences and endogenous viral element identified in the small hive beetle, Aethina tumida Murray.

Abstract

The small hive beetle (SHB), Aethina tumida Murray is an invasive pest of the honey bee. This beetle feeds not only on bee resources within the hive such as honey and pollen, but also on bee brood and dead bees. The impact of this beetle's intimate parasitic association with the honey bee on virus transmission is poorly understood. We aimed to characterize the virome of SHB to identify SHB viruses with potential for use in biological control of this pest. We characterized the virome of SHB by sequencing the transcriptomes and small RNAs of SHB collected from multiple geographical regions: Adult and larval SHB were collected from midwestern- (Illinois, Ohio) and southern- (Florida, Texas) states of the USA, and from South Africa. Small RNAs were sequenced for adult beetles from Florida and Ohio, for larvae from Florida, and for an SHB-derived cell line (BCIRL-AtumEN-1129). Assembled transcripts were annotated by BLASTx. In field-caught adult beetles and adults and larvae from South Africa, the near-complete sequences for all three genomic segments of a putative novel phasmavirus (order: Elliovirales, formerly Bunyavirales) were identified. In addition, transcripts from a partial glycoprotein sequence from a different phasmavirus integrated into the genome of SHB were detected in all samples, including the SHB-derived cell line. Apparent PIWI-interacting RNAs derived from the integrated glycoprotein sequence were also detected. Whether the putative extant phasmavirus replicates in SHB and has potential as a biological control agent for SHB remain to be determined.