Not truly a synonym: The psyllid galling Syzgium in N. America was MISTAKENLY identified as T. eugeniae for many years

Trioza eugeniae

Triozidae

Trioza

Metrosideros spp

Syzygium paniculatum

California

Syzygium smithii

Trioza adventicia

 After eggs hatch, newly emerged nymphs crawl to the undersides of leaves where they settle, become immobile and feed by sucking sap ... Feeding causes a pit to develop around each yellowish, scale-like nymph. Excessive pit formation creates severely distorted or blistered leaves and shoots which appear stunted. 

Biology and Management of the Eugenia Psyllid (Trioza eugeniae Froggatt)

The ‘Eugenia psyllid’ or ‘Lilly pilly psyllid’, widely recognized in Australia and in the USA as Trioza eugeniae Froggatt (Hemiptera: Triozidae), is not T. eugeniae, but rather T. adventicia Tuthill. 

Case of mistaken identity: resolving the taxonomy between Trioza eugeniae Froggatt and T. adventicia Tuthill (Psylloidea: Triozidae)

<b>Hosts</b>
Metrosideros spp added based on statement that "the eugenia psyllid . . . which in its native range feeds on Syzygium host species, has expanded its host range to include another introduced myrtaceous genus, Metrosideros, in California" on page 5 of Percy et al., An annotated checklist of the psyllids of California (Hemiptera: Psylloidea), Zootaxa 3193: 1–27 (2012), https://www.mapress.com/zootaxa/2012/f/zt03193p027.pdf. The article refers to "Trioza eugeniae," based on the then-accepted misidentification of T. adventicia, and does not address whether the psyllid causes galls on Metrosideros. 