Strange little cases built with three offset chambers. About 12mm long overall. Several were found on a single callistemon plant always about midway on a stem. This is Tortricidae, Olethreutinae, Eucosmini, Spilonota sp.
This gall forming scale bug (Apiomorpha munita, family = Eriococcidae) produces a chemical stimulant causing the plant to grow a protective cage. The smaller posterior structures are (empty) male galls. The dissection shows the adult female prisoner with reduced wings, legs, antennae etc.