A new apionine genus and species, Diselmobius lechi, is described from Tasmania, based on four females collected on the Cupressaceae Diselma archeri Hooker in Cradle and Field Mountains. It represents the fourth distinct apionine lineage in the fauna of Australia, being compared with the Australian Rhinorhynchidius Voss and New Zealand Strobilobius Kuschel, both associated with the gymnosperm family Cupressaceae. Due to unknown male characters, the tribal placement of Diselmobius within Apioninae remains uncertain.