Technical Abstract: Invertebrate iridescent virus 6 (IIV6) was determined to cause infection in Phyllophaga vandinei Smyth, through a range of modes of transmissions. This is the first evidence of IIV6 infection in P. vandinei, which caused both patent and sub-lethal covert infections in larvae and adults. Mortality rates were determined to be ~30% when virus inoculum was injected into larvae or adults. Adults injected with virus showed dramatically altered behaviour; injected beetles were not observed feeding or mating and fewer adults were observed emerging from the soil at night when compared with adults injected with buffer or adults that were not injected. Tissue collected from infected adults resulted in infection when injected in healthy adults, as confirmed with PCR. PCR also confirmed that frass of infected larvae and adults contained virus and when reconstituted frass was injected into healthy adults or larvae they become infected. Non virus exposed, healthy adults were infected by coming into contact with soil or plant material that had been exposed to infected adults as much as two weeks prior to introduction of healthy adults. Although relatively low mortality resulted when adults or larvae were injected with the virus, the demonstration of horizontal transmission, potentially through frass of infected individuals, identifies a mode of transmission which may be exploited to use the virus as a potential management tool to reduce P. vandinei populations.