Abstract
Norfolk Island is a small, isolated archipelago in the Pacific Ocean, 1400 km east of the Australian mainland. The history of human colonisation and land use on the island has resulted in a substantial reduction in the extent and quality of indigenous habitat. A quarantine survey of Norfolk Island in 2012-2014 provided the first records of psyllid species, reporting six taxa from the island. Additional collection records are provided that increase the number to 14 species, of which nine are regarded as adventive, four as native of which two are endemic, and one whose additional distribution is unknown. Two species are formally described here and are the first psyllid species to be described from Norfolk Island. These new species, Pseudophacopteronaewagriini Percy & Martoni, sp. nov. (Aphalaridae) and Acizziaaliceae Percy & Martoni, sp. nov. (Psyllidae) are both considered endemic to Norfolk Island and are associated with native plants, the endemic Alyxiagynopogon (Apocynaceae) and the native Dodonaeaviscosa (Sapindaceae), respectively. In addition to an updated checklist, identification keys to adults and immatures of the psyllids found on Norfolk Island and DNA barcodes for all species are provided. Both new species have had complete mitochondrial genomes sequenced in a previous study and here a full annotation of the mitochondrial genome of Acizziaaliceae Percy & Martoni, sp. nov. is supplied. Lastly, the barcode data was analysed in a maximum likelihood constraint framework with previous genome data to investigate the phylogenetic origins of the Norfolk Island taxa.