Pathogenicity and transmission dynamics of Gryllus bimaculatus densovirus (GbDV), a significant pathogen in cricket farms in South Korea

Since 2023, Gryllus bimaculatus Densovirus (GbDV) has emerged as an important pathogen on cricket farms in South Korea, causing severe mortality and economic losses. This study evaluated the pathogenicity and transmission potential of GbDV using injection challenge, oral ingestion, airborne exposure, and colony assays conducted across different initial infection-prevalence levels. Injection caused a rapid decline in survivorship. Post-injection ΔCt patterns suggested that the earliest deaths were influenced, at least in part, by the injection procedure, whereas deaths from Day 5 onward were more consistent with viral replication. Oral ingestion of a 1:1000 diluted inoculum significantly reduced survivorship, supporting oral transmission. By contrast, airborne exposure under laboratory conditions did not reveal a measurable effect on survivorship. In colony assays, survivorship declined progressively as initial infection prevalence increased, indicating that higher prevalence markedly amplified colony-level mortality risk. Together, these results show that GbDV has high pathogenic potential in mass-reared crickets and support practical management centered on feed hygiene, rapid pathogen screening, and screening/quarantine before introducing new stock into established colonies.