The discovery of a remarkable new palm bug species on Norfolk Island brings into question its systematic position within the family Thaumastocoridae, and the validity and biogeography of the three extant subfamilies. Latebracoris norfolcensis gen. nov., sp. nov. is described from remote Norfolk Island in the Southwest Pacific. The species was found on the native Norfolk Island palm Rhopalostylis baueri. The formal description of the species includes fine details of external non-genitalic and genitalic characters, supported with images from light and scanning electron microscopy. Details of the egg are described, including the shape and micropylar configuration. All nymphal stages are diagnosed morphologically and morphometrically, with the segregation of the five instars using the Brooks–Dyar Rule. The natural history of the Norfolk Island Palm Bug is documented, including the oviposition site of eggs, and microhabitat of nymphs and adults on palm infructescences, with hypotheses about development in relation to reproductive succession of the palm host. The systematic position of the Norfolk Island Palm Bug is assessed through a phylogenetic analysis of a selection of taxa of the superfamily Miroidea, using the parsimony criterion. The phylogenetic analyses were partitioned into Recent and fossil taxa, revealing monophyly of the Thaumastocoridae, and the subfamilies Thaumastocorinae and Xylastodorinae, with synapomorphy and significant resampling support. The Thaicorinae are verified as synonymous with the Xylastodorinae. The monotypic fossil subfamily Thaumastotinginae is removed from the Thaumastocoridae and treated as incertae familiae. Suprageneric relationships were corroborated in the two taxon partition analyses. An overview of host associations is given verifying palm specialism for the Xylastodorinae. The natural history, palm specialism, biogeography, morphology and systematics of the Xylastodorinae and allies are discussed in light of the discovery of Latebracoris norfolcensis.

ZooBank: urn:lsid:zoobank.org:pub:40A20DE4-6489-4B67-BF2E-0B7256BA1CD1