One virus, three kingdoms

De Medeiros and co-workers find that the insect which transmits tomato spotted wilt tospovirus carries a putative transcription factor necessary for viral replication. Fair enough, you might say - the virus is piggy-backing on insect metabolism en route to the next tomato. However, the insect, so helpful with regard to provision of this transcription factor, suffers infection during the process i.e. is ill. So what are the constraints that prevent the insect discarding this exploitable back door? Or is there a hidden benefit? Extra oddity: the expression of the putative transcription factor in human cells allows the virus to replicate (but not infect) there.