An annotated checklist of the psyllids (Hemiptera, Psylloidea) of Norfolk Island with keys to species, new records, and descriptions of two new endemic species

Francesco Martoni; James M. H. Tweed; Mark J. Blacket; Diana M. Percy

doi:10.3897/zookeys.1238.124535

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, Pseudophacopteron aewagriini Percy & Martoni, sp. nov. (Aphalaridae) and Acizzia aliceae Percy & Martoni, sp. nov. (Psyllidae) are both considered endemic to Norfolk Island and are associated with native plants, the endemic Alyxia gynopogon (Apocynaceae) and the native Dodonaea viscosa (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 Acizzia aliceae 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.

Key words:

Acizzia, Alyxia, Australia, Dodonaea, endemism, New Zealand, Pseudophacopteron, Southwest Pacific, taxonomy

Introduction

The Norfolk Island group is a small, isolated archipelago located in the southwest Pacific Ocean (29.0408°S, 167.9547°E). Norfolk Island itself is the largest island in the group (35.6 km²) reaching an elevation of 319 m a.s.l., while the smaller Phillip (1.95 km²) and Nepean (0.09 km²) islands are located 5.8 km and 0.8 km to the south of Norfolk, respectively. New Caledonia and New Zealand are the nearest major landmasses and are located approximately 700 km to the north and south, respectively, while Lord Howe Island and mainland Australia lie approximately 900 km and 1,400 km to the west, respectively. The island group, referred to here as Norfolk Island for simplicity, has been heavily impacted by humans, particularly following colonisation by Europeans in 1788, with much of the indigenous vegetation cleared to make way for agriculture (Levin and Kark 2023). Only relatively small areas of indigenous vegetation remain, most of which occur within the Mt Pitt section of Norfolk Island National Park (Invasive Species Council 2021).

The superfamily Psylloidea (Hemiptera: Sternorrhyncha) is composed of almost 4000 described species worldwide (Ouvrard 2020), across seven different families (Burckhardt et al. 2021), including a few economically important species known to vector plant pathogens (Jagoueix et al. 1994; Liefting et al. 2009; Munyaneza et al. 2010). Like many invertebrate taxa from Norfolk Island, the psyllid fauna is poorly known. An extensive quarantine survey between 2012 and 2014 produced the first records of psyllids from Norfolk Island, as well as the first records for many other taxa (Walker et al. 2015; Maynard et al. 2018). Prior to this, no psyllids had been reported from Norfolk Island (Smithers 1998).

A total of six psyllid species belonging to three different families were recorded: three Aphalaridae, one Carsidaridae, and two Triozidae (Maynard et al. 2018). At the time, the Norfolk Island psyllid fauna included introductions of taxa native to the two countries with closest economic and political ties, Australia (three species) and New Zealand (two species), while a single species appeared to be native to the area. In recent years, increasing efforts have been focused on exploring the psylloid diversity of the Southwest Pacific region (Martoni et al. 2016, 2024; Martoni and Brown 2018). The geographical location of Norfolk Island puts it in a central position between New Zealand, Australia and New Caledonia, giving the archipelago an important role in evaluating biogeographic distributions as well as anthropogenic-mediated dispersal and introduction of species due to high movement of people and produce. For these reasons, during a 2022 survey conducted to target plant pests and pathogens (Martoni et al. 2023), psyllids were targeted for collection.

In this study, we provide an updated and annotated checklist for the psyllids of Norfolk Island. We record eight previously unreported taxa and provide formal descriptions of two new species representing the first endemic psyllids described from Norfolk Island. We also provide identification keys to adults and immatures, and list DNA sequence resources (previous and newly generated) for these taxa. Lastly, we investigate the phylogenetic origins of the Norfolk Island psyllids using a maximum likelihood backbone constraint analysis.

Materials and methods

Sampling and field collections

Fresh specimens were collected by FM, MJB and JMHT during field trips in March and October 2022, February and March 2023, and October and November 2023. Collections were made by beating foliage over a beating tray. Numerous tree and shrub species were examined as potential psyllid hosts, based on the presence of psyllids from these host genera in other regions. These included species of Acacia, Alyxia, Casuarina, Celtis, Dodonaea, Eucalyptus, Ficus, Leucaena, Melicope, Myoporum, Nestegis, Pisonia, Pittosporum, Planchonella, and Zanthoxylum. Insect specimens were preserved in high grade ethanol (> 80%) for further analysis. Type material and additional material examined is deposited in the Australian National Insect Collection (ANIC) in Canberra, in the Victorian Agricultural Insect Collection (VAIC) in Bundoora, and in the Naturhistorisches Museum of Basel (NHMB), Switzerland. Additional material examined by DMP, originally collected during the Norfolk Island Quarantine Survey 2012–2014 (Maynard et al. 2018), is preserved at the University of British Columbia (DMPC).

Specimen preparation, measurements, drawings, and photographs

Microscope slide preparation, following the work of Taylor et al. (2016), was performed on 20 adult specimens, ten individuals (5 males and 5 females) of Pseudophacopteron aewagriini Percy & Martoni, sp. nov. and ten individuals (5 males and 5 females) of Acizzia aliceae Percy & Martoni, sp. nov. Additionally, three immature specimens of Acizzia aliceae Percy & Martoni, sp. nov. and four immature specimens of Pseudophacopteron aewagriini Percy & Martoni, sp. nov. were mounted on two separate slides.

General morphology of adult characters follows that presented in the works of Taylor et al. (2016), Martoni and Blacket (2021), and Martoni et al. (2024), and it has been summarized in Fig. 1 for the purpose of the adult key presented here. Immature characters used in the key reference Taylor (1962, 1985, 1990), White and Hodkinson (1985), and Muddiman et al. (1992). Genus-specific measurements and ratios follow the work of Martoni and Armstrong (2019) for Acizzia, and Malenovský and Burckhardt (2009) and Malenovský et al. (2015) for Pseudophacopteron. High-resolution automontage photographs of adults were obtained using the Leica Application Suite software (version 4.5.0), from 5–20 stacked images obtained using a Leica stereo microscope M205C with a DFC450 camera (Leica Camera, Wetzlar, Germany). Additionally, a Hitachi TM3030Plus Tabletop Scanning electron microscope was used for close-up details (Hitachi, Tokyo, Japan). For the examination and high-resolution photographs of microscope slides, a Leica DM6 B microscope was used with a Leica DMC4500 camera (Leica Camera, Wetzlar, Germany) with additional images taken with a Zeiss Axioscope A1 microscope with Zeiss Axiocam 305 camera and stacked using HeliconFocus (v. 8.2.18). Measurements were obtained using the Leica ‘Segment Line Tool’ option.

Figure 1.

Morphological terminology A fore wing veins B cells C cell values and measurements D head, including measurements E female terminalia.

High resolution photos were then collated into plates using the GNU Image Manipulation Program (GIMP) version.2.10.6. The line drawings were made using the software Inkscape v.1.2.2.

Molecular analysis

DNA was non-destructively extracted from a total of 33 single specimens using the protocol of Martoni et al. (2020). A fragment of the subunit I of the cytochrome oxidase gene (COI) barcode region (Hebert et al. 2003) of ~ 570 bp was targeted using the primers Psy-COI-F3 (5’-ACAATTGTTACWGCWCAYGC-3’; Martoni et al. 2020) and HCO2198 (5’-TAAACTTCAGGGTGACCAAAAAATCA-3’; Folmer et al. 1994). The polymerase chain reaction (PCR) was performed using the MyFi kit (Bioline Meridian Biosciences, Cincinnati, USA) following the manufacturer’s instructions and the following cycle: initial denaturation at 95 °C for 5 min, followed by 40 cycles of 30 s at 94 °C, 30 s at 50 °C and 1 min at 72 °C, and a final elongation of 7 min at 72 °C. PCR products were Sanger sequenced in both directions commercially (Macrogen, Seoul, Korea). The electropherograms were manually examined and checked for pseudogenes and stop codons using the software MEGA X (Kumar et al. 2018). Forward and reverse sequences were combined in MEGA X and each sequence was blasted against the online databases GenBank and BOLD to assess similarities to other taxa. The sequences obtained were uploaded on the NCBI GenBank database, with accession numbers OR558292–OR558323, PQ999102 (Table 1).

Table 1.

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Norfolk Island specimens used for molecular analysis in this study and in Percy et al. (2018). The table includes information on the species recorded, including family, GenBank accession numbers for different genes, and collection dates. Accession numbers in bold were generated in this study.

Species	Family	Acc. Number	Gene	Coll. date
Blastopsylla occidentalis	Aphalaridae	OR558304, OR558305	COI	Oct-2022
		MG988657	COI	Dec-2012
		MG988950	cytB	Dec-2012
Cardiaspina fiscella	Aphalaridae	OR558322, OR558323	COI	Oct-2022
Cryptoneossa triangula	Aphalaridae	OR558292	COI	Mar-2022
Glycaspis granulata	Aphalaridae	OR558310, OR558311	COI	Oct-2022
Pseudophacopteron aewagriini Percy & Martoni, sp. nov.	Aphalaridae	OR558312–OR558315	COI	Oct-2022
		MG988814	COI	Jul-2013
		MG988815	COI	Oct-2013
		MG989134	cytB	Oct-2013
		MG989135	cytB	Jul-2013
		MG989234	mitogenome	Jul-2013
Mesohomotoma hibisci	Carsidaridae	OR558306, OR558307	COI	Oct-2022
		KY294175	COI	Dec-2012
		KY294659	cytB	Dec-2012
Acizzia acaciaebaileyanae	Psyllidae	OR558293–OR558296	COI	Feb-2023
		MG988623	COI	Jul-2013
		MG988894	cytB	Jul-2013
Acizzia hakeae	Psyllidae	PQ999102	COI	Nov-2024
Acizzia sp. A	Psyllidae	OR558303	COI	Oct-2022
Acizzia sp. B	Psyllidae	OR558297–OR558300	COI	Feb-2023
Acizzia aliceae Percy & Martoni, sp. nov.	Psyllidae	OR558301, OR558302; OR558308, OR558309	COI COI	Feb-2023; Oct-2022
		MG988625	COI	Jul-2013
		MG988895	cytB	Jul-2013
		PQ754209	mitogenome	Jul-2013
Heteropsylla cubana	Psyllidae	OR558320, OR558321	COI	Oct-2022
Bactericera cockerelli	Triozidae	OR558318, OR558319	COI	Mar-2022
Powellia vitreoradiata	Triozidae	OR558316, OR558317	COI	Oct-2022
		KY294138	COI	Dec-2012
		KY294622	cytB	Dec-2012

Complete mitochondrial genomes for the two endemic species described here were generated in a previous study (Percy et al. 2018). For this study, the mitochondrial genome of Acizzia aliceae Percy & Martoni, sp. nov. has been annotated using Geneious R8 v8.1.9 (Biomatters Ltd., Kearse et al. 2012) and submitted to GenBank with accession number PQ754209.

To place the Norfolk Island species within the Psylloidea superfamily phylogeny presented in Percy et al. (2018), a maximum likelihood (ML) constraint analysis was run with RAxML v. 8.2.12 (Stamatakis 2014) on the CIPRES Science Gateway (Miller et al. 2010). The constraint analysis allows the placement of short DNA sequences within the broader phylogenetic framework with improved resolution. The constraint tree used was the total evidence tree obtained from the mitogenome data in Percy et al. (2018). The constraint tree option allows the user to specify an incomplete multifurcating constraint tree for the RaxML search. Initially, multifurcations are resolved randomly and the additional taxa are added using a maximum parsimony criterion to compute a comprehensive (containing all taxa) bifurcating tree (Stamatakis 2014). This tree is then further optimized under ML criteria respecting the given constraints with the added taxa unconstrained (i.e., can be placed in any part of the tree). Data partitions were specified for codon position and RNA regions, and ML search criteria employed model GTRCAT, 1000 rapid bootstraps, and Gamma optimisation of tree space.

Threat classification

The threat status of species endemic to Norfolk Island was assessed as per the IUCN (2012) criteria. Occurrence records were compiled from collected specimens as well as confirmed identifications from iNaturalist (https://www.inaturalist.org/), and observational data provided by colleagues in the field. Extent of occurrence (EOO) for each species was calculated by generating convex hulls with the minimum bounding geometry function of QGIS. Area of occupancy (AOO) was calculated based on a 4 km² grid overlain on Norfolk Island.

Results

Key to the psyllids of Norfolk Island (adults)

1	Fore wing with R+M+Cu stem trifurcating into veins R, M and Cu (Fig. 2A, B) (Triozidae)	2
–	Fore wing with R+M+Cu stem bifurcating into veins R and M+Cu (Fig. 2C) (other families)	3
2	Fore wing apex bluntly acute, with vein Rs long, reaching margin of wing closer to wing apex (distance between apices of veins Rs and M₁₊₂ subequal or less than distance between M₁₊₂ and M₃₊₄), bifurcation of vein M into M₁₊₂ and M₃₊₄ anterior to line connecting apices of veins Rs and Cu_1a, shape of cell cu₁ higher, with cu₁ value < 2 (Fig. 2A). On Pittosporum spp. (Pittosporaceae)	*Powellia vitreoradiata*
–	Fore wing apex acute, with vein Rs shorter (distance between apices of veins Rs and M₁₊₂ much greater than distance between M₁₊₂ and M₃₊₄), bifurcation of vein M into M₁₊₂ and M₃₊₄ at or posterior to line connecting apices of veins Rs and Cu_1a, shape of cell cu₁ lower, with cu₁ value 2 or greater (Fig. 2B). On Solanum and Capsicum spp. (Solanaceae)	*Bactericera cockerelli*
3	Fore wing with veins Rs and M₁₊₂ either connected by a cross vein (Fig. 2C) or meeting at a contact point (Fig. 3A)	4
–	Fore wing with veins Rs and M₁₊₂ not connected or contacting (Fig. 3B, C)	5
4	Fore wing with no markings on membrane, apex bluntly acute, cell cu₁ narrower than m₁, costal break absent (Fig. 2C). On Hibiscus tiliaceus (Malvaceae)	*Mesohomotoma hibisci*
–	Fore wing with dark markings on membrane around the base and posterior margin, apex broadly rounded, cell cu₁ wider than m₁, costal break present (Fig. 3A). On Alyxia gynopogon (Apocynaceae)	Pseudophacopteron aewagriini Percy & Martoni, sp. nov.
5	Fore wing with vein R longer than M+Cu (Fig. 3B). On Fabaceae and Sapindaceae (Acacia, Leucaena, Dodonaea)	6 (Psyllidae)
–	Fore wing with vein R shorter than M+Cu (Fig. 3C). On Myrtaceae (mostly Eucalyptus)	11 (Aphalaridae)
6	Fore wing with broad, short, somewhat triangular pterostigma (~ 0.3 × wing length), shorter Rs vein (~ 0.5 × fore wing length), low cell cu₁ with value higher than 2 (height of cell cu₁ ~ 0.18 × wing width) (Fig. 3D). Male terminalia with paramere deeply bifid, the two parts divided almost to the base, male proctiger without distinct posterior lobe. On Leucaena	*Heteropsylla cubana*
–	Fore wing with narrower and longer pterostigma (length 0.44–0.48 × wing length), longer Rs vein (length > 0.6 × fore wing length), high cell cu₁ with values reaching maximum 1.5 (height of cell cu₁ 0.27–0.33 × wing width) (Fig. 4G). Male terminalia with paramere not divided, male proctiger with distinct posterior lobe. On Acacia or Dodonaea	*7 (Acizzia)*
7	Fore wing membrane with distinct spotted or banded markings, often creating Y shapes at the apical margins of cells (Fig. 4A, C, E, F). On Acacia	8
–	Fore wing membrane without distinct markings of spots or bands, either clear or yellowish (Fig. 4G). On Dodonaea viscosa	Acizzia aliceae Percy & Martoni, sp. nov.
8	Larger species (total length ~ 3 mm, and fore wing length ~ 2 mm). Fore wing membrane with darker patches in the central part of the wing and around Cs (Fig. 4A). Host plant unknown	Acizzia sp. “A”
–	Smaller species (total length ~ 2 mm, and fore wing length usually < 1.7 mm). Fore wing with spots more scattered and not forming large patches (Fig. 4C, E, F). On Acacia, Hakea or Grevillea	9
9	Fore wing with vein M strongly arcuate, also other veins more curved, particularly M₁₊₂ and M₃₊₄ and where vein Cu_1b meets wing margin (Fig. 4C, E), cell m₁ high and narrow (height:width ratio > 2.35). Fore wing longer than 1.6 mm	10
–	Fore wing with vein M only slightly arcuate, veins M₁₊₂ and M₃₊₄ only slightly curved (Fig. 4F), cell m₁ lower and broader (height:width ratio < 2.2). Fore wing shorter than 1.6 mm. On Acacia podalyriifolia	*Acizzia acaciaebaileyanae*
10	Female proctiger strongly curved downward, with pronounced post-anal bump covered in dense setae, anal ring length ~ 1/3 proctiger length (Fig. 4B). On Acacia spirorbis	Acizzia sp. “B”
–	Female proctiger gradually sloping downward, without post-anal bump, surface with only few, sparse setae, anal ring length ~ 1/2 proctiger length (Fig. 4D). Host plant not confirmed on Norfolk Island, but on Hakea and Grevillea elsewhere	*Acizzia hakeae*
11	Head with genal processes as long or longer than vertex length (Fig. 5A). Fore wing elongate, length ≤ 3 mm, and narrow (ratio fore wing length:width ~ 3.5), apex subacute (Fig. 5D)	*Glycaspis granulata*
–	Head with genal processes shorter than vertex length, and either broad (Fig. 5B) or otherwise very short, < 1/2 the vertex length (Fig. 5C). Fore wing broader and generally shorter (ratio fore wing length:width 2.4–2.9), apex rounded (Fig. 5E–G)	12
12	Larger species; fore wing length always greater than 2 mm (female fore wing often reaching 3 mm), with reddish veins, short pterostigma (~ 0.25 × wing length), long veins M₁₊₂ and M₃₊₄ making the m₁ cell value ~ 2 (Fig. 5E). Head with genal processes longer (> 0.5 × vertex length), broader, and contiguous medially (Fig. 5B). On Eucalyptus (immature stages producing lerps)	*Cardiaspina fiscella*
–	Smaller species; fore wing length always < 2 mm, with brown veins, longer pterostigma (~ 0.5 × wing length), shorter veins M₁₊₂ and M₃₊₄ making the m₁ cell value 1–1.7 (Fig. 5F, G). Head with genal processes shorter (< 0.5 × vertex length) and narrower, diverging or not but not contiguous medially (Fig. 5C). On Eucalyptus (immature stages free-living)	13
13	Fore wing clear in the center and becoming darker towards the apex, vein Cu_1b longer, cu₁ cell value lower than 2 (Fig. 5F). Head with genal processes diverging (Fig. 5C)	*Blastopsylla occidentalis*
–	Fore wing transparent throughout, vein Cu_1b shorter, cu₁ cell value higher than 2 (Fig. 5G). Head with genal processes not diverging	*Cryptoneossa triangula*

Figure 2.

Fore wing (females) A Powellia vitreoradiata B Bactericera cockerelli C Mesohomotoma hibisci. Trifurcation (A, B) and bifurcation (C) of R+M+Cu stem are circled with a dotted line. Scale bar: 1 mm.

Figure 3.

Fore wing (females) A Pseudophacopteron aewagriini Percy & Martoni, sp. nov. B, D Heteropsylla cubana (Psyllidae) C Blastopsylla occidentalis (Aphalaridae), showing the different morphology of vein branching, with dashed lines highlighting relative proportion of veins. Scale bar: 1 mm (A, D figures B and C are not to scale)

Figure 4.

Fore wing and terminalia (females) of Psyllidae species A Acizzia sp. “A” B, C Acizzia sp. “B” D, E Acizzia hakeae F Acizzia acaciaebaileyanae G Acizzia aliceae Percy & Martoni, sp. nov. Scale bars: 0.2 mm (B, D); 1 mm (A, C, E–G).

Figure 5.

Head (black arrow pointing at length of genal processes, GCL, and of vertex, VL) and fore wings (females) A, D Glycaspis granulata B, E Cardiaspina fiscella C, F Blastopsylla occidentalis G Cryptoneossa triangula (G). Scale bars: 0.2 mm (A–C); 1 mm (D–G).

Key to the psyllids of Norfolk Island (5^th instar immatures)

1	Body with a ring of truncate marginal setae present around entire margin of body (Fig. 6A)	2
–	Body without a ring of truncate setae on margin of body (Fig. 6F)	4
2	Humeral lobes of fore wing pads large, extending almost to anterior margin of eye (Fig. 6B)	3
–	Humeral lobes lacking, forewing pads with at most slight anterior bulge (Fig. 8G). Immatures in individually isolated open pit galls on the upper leaf surface of Alyxia gynopogon (Apocynaceae) (Fig. 7A–C)	Pseudophacopteron aewagriini sp. nov.
3	Circumanal ring relatively wide and markedly antero-posteriorly constricted (Fig. 6C lower). Immatures, often in aggregates, making shallow pits or depressions on the upper or lower leaf surface of Pittosporum spp. (Pittosporaceae) (Fig. 7F)	*Powellia vitreoradiata*
–	Circumanal ring relatively narrow and not markedly antero-posteriorly constricted (Fig. 6C upper). Immatures free-living but can cause leaf distortion and discolouration. On Solanum and Capsicum spp. (Solanaceae)	*Bactericera cockerelli*
4	Caudal plate distinctly pointed at apex (Fig. 6D). Immatures producing lerps (Fig. 7D). On Eucalyptus (Cardiaspina and Glycaspis)	5
–	Caudal plate narrowly or broadly rounded, not distinctly pointed at apex (Fig. 6F–H). Immatures free-living but can be covered in filamentous exudate (Fig. 7E). On Eucalyptus or other host plants	6
5	Antenna shorter than head width. Shape of lerp bivalve shell-like with woven basket-like construction (Fig. 7D). On Eucalyptus (Myrtaceae)	*Cardiaspina fiscella*
–	Antenna longer than head width. Shape of lerp is rectangular, with a dense jumble of filaments that often extend out from the cone. On Eucalyptus (Myrtaceae)	*Glycaspis granulata*
6	Antenna shorter than head width and fore wing pad length (Fig. 6F). Abdominal pores present in small clusters on dorsal surface only. On Eucalyptus (Blastopsylla and Cryptoneossa)	7
–	Antenna longer than head width and fore wing pad length (Fig. 12G). Abdominal pores absent or if present, in wide bands on both dorsal and ventral surfaces (Fig. 6H). On other host plants	8
7	Smaller species (Fig. 6F left), body length ~ 1 mm, head width ~ 3/4 abdomen width. Antenna length ~ 0.7 × fore wing pad length. Anus with distinct circumanal ring	*Blastopsylla occidentalis*
–	Larger species (Fig. 6F right), body length ~ 1.4 mm, head width ~ 2/3 abdomen width. Antenna length ~ 0.5 × fore wing pad length. Anus without distinct circumanal ring (composed of isolated pores)	*Cryptoneossa triangula*
8	Abdomen with 3+3 or 4+4 lanceolate setae on margin (Fig. 6G). On Leucaena (Fabaceae)	*Heteropsylla cubana*
–	Abdomen lacking lanceolate setae on margin	9
9	Abdomen with anal pores in irregular bands; anus terminal. On Hibiscus tiliaceus (Malvaceae) (Fig. 6H)	*Mesohomotoma hibisci*
–	Abdomen without bands of anal pores; anus ventral (Fig. 12G). On other plants	10
10	Abdomen with capitate setae on margin. On Dodonaea, Hakea or Grevillea	11
–	Abdomen without capitate setae (at most 1 or 2 pairs of short simple setae) on margin. On Acacia (Fabaceae)	*Acizzia acaciaebaileyanae*
11	Abdomen with 4+4 long, slender, narrowly capitate setae on margin (Fig. 12G). Circumanal ring almost horizontal (Fig. 12J). On Dodonaea (Sapindaceae)	Acizzia aliceae Percy & Martoni, sp. nov.
–	Abdomen with 6+6 short, robust, broadly capitate setae on margin. Circumanal ring strongly V-shaped. Host plant not confirmed on Norfolk Island, but on Hakea and Grevillea (Proteaceae) elsewhere	*Acizzia hakeae* ¹

Figure 6.

Illustrations of immature characters used in the key (if with longitudinal division, dorsal on left and ventral on right) A Example of marginal ring of truncate setae B humeral lobes of triozid species C circumanal ring shape of Bactericera cockerelli (top) and Powellia vitreoradiata (bottom) D apex of abdomen in Cardiaspina E apex of abdomen in Glycaspis F size and structural difference between Blastopsylla (left) and Cryptoneossa (right), showing detail of circumanal rings G abdomen of Heteropsylla cubana showing placement of paired lanceolate setae H abdomen of Mesohomotoma hibisci showing bands of pores and indicating terminal position of anus. Some images redrawn with reference to Taylor (1962, 1985, 1990), White and Hodkinson (1985), and Muddiman et al. (1992). Scale bars: 0.1 mm (C); 0.25 mm (F).

Figure 7.

Psyllids on their host plants A damage caused by the open pit galls of Pseudophacopteron aewagriini Percy & Martoni, sp. nov. on the leaves of Alyxia gynopogon B same, detail of distribution of galls on the upper leaf surface C close up of immatures (orange) seated in the pit galls on the upper leaf surface D lerp of Cardiaspina fiscella on leaves of Eucalyptus sp., the lerp is built by the immatures which live underneath until adulthood E cluster of both immatures and adults of Mesohomotoma hibisci on the new growth of Hibiscus tiliaceus showing production of white waxy filaments F damage caused by Powellia vitreoradiata on Pittosporum bracteolatum, showing the presence of shallow pit galls.

Checklist of Norfolk Island Psylloidea

Family Aphalaridae

Subfamily Phacopteroninae

Pseudophacopteron aewagriini Percy & Martoni, sp. nov.

https://zoobank.org/1C9C6FF5-CCB7-4598-A357-EA7B6B05AEC1

Figs 8, 9, 10

Type locality.

Norfolk Island, Norfolk Island National Park, Red Road Track, on Alyxia gynopogon on side of track. Dislodged beating host plant onto tray and collected using entomological aspirator.

Type material.

Holotype : Norfolk Island • 1 adult ♂; Norfolk Island National Park, Red Road Track; 17 Oct. 2022; Francesco Martoni leg.; on Alyxia gynopogon; sweeping; entire specimen mounted on card triangle, deposited at VAIC. Labels: “Norfolk Island N.P. / Red Road Track / 17-Oct-2022 F. Martoni / On Alyxia gynopogon” (printed on white card); “HOLOTYPE ♂ / Pseudophacopteron aewagriini / Percy and Martoni 2025” (printed on red card). Paratypes: Norfolk Island • 5 adult ♂♂, 5 adult ♀♀; same data as the holotype, dissected specimens mounted on microscope slides, deposited at VAIC • 1 adult ♂, 2 adult ♀♀; same data as the holotype, entire specimens mounted on card triangle, deposited at ANIC • 16 adult ♂♂, 18 adult ♀♀; Norfolk Island National Park, Bridle Track; 15 Oct. 2023; James M.H. Tweed leg.; on Alyxia gynopogon; entire specimens preserved in ethanol, deposited at VAIC • 2 adult ♂♂, 2 adult ♀♀, same as for preceding; entire specimens preserved in ethanol, deposited at NHMB • ~ 200 immatures; Norfolk Island National Park, Red Road Track car park; 08 Nov. 2023; James M.H. Tweed leg.; on Alyxia gynopogon; entire specimens preserved in ethanol, deposited at VAIC • 1 adult ♂, 3 adult ♀♀; Norfolk Island National Park, Forbidden Track; 20 Feb. 2023; James M.H. Tweed leg.; On Alyxia gynopogon; entire specimens preserved in ethanol, deposited at VAIC • 3 adult ♂♂; Norfolk Island National Park, Red Road Track; 15 Oct. 2022; Francesco Martoni leg.; on Alyxia gynopogon; entire specimens preserved in ethanol, deposited at VAIC • 4 adult ♂♂; Norfolk Island National Park, Palm Glen; 11 Jul. 2013; Alice Wells leg.; on Alyxia gynopogon; AW-12-95; entire specimens preserved in ethanol, deposited at DMPC • 3 adult ♂♂, 2 adult ♀♀,; Norfolk Island National Park, Palm Glen; 22 Oct. 2013; Laurence Mound leg.; on Alyxia sp.; LAM5815; entire specimens preserved in ethanol, deposited at DMPC. All paratypes are labelled as “PARATYPE ♂-♀ / Pseudophacopteron aewagriini / Percy & Martoni 2025” (printed on blue card).

Other material examined.

Norfolk Island • ~ 20 immatures; Norfolk Island National Park, Red Road Track; 14 Mar. 2022; Francesco Martoni leg.; on Alyxia gynopogon; entire specimens preserved in ethanol, deposited at VAIC. Not included in the type series because they were damaged during a semi-destructive DNA extraction protocol.

Diagnosis.

The shape of the fore wing of P. aewagriini, which is elongate and narrow (> 2.6 × longer than wide), as well as the pigmentation pattern, clearly aligns this taxon with other Pseudophacopteron in the Austro-Pacific region (Malenovský 2008); the type species, P. tuberculatum Crawford, as well as most other taxa also found on Apocynaceae host plants, have a fore wing that is pyriform and broad (length < 2.6 × width) (Malenovský 2008; Malenovský and Burckhardt 2009; Malenovský et al. 2015). A similar narrow wing morphology to that of P. aewagriini can be observed in some of the African Pseudophacopteron species such as P. nigritulum Malenovský and Burckhardt and P. wagneri Malenovský and Burckhardt (Malenovský and Burckhardt 2009), but in these cases the vertex lacks a distinct median ridge, and only P. wagneri is possibly associated with Apocynaceae. See also the Remarks section below.

Description.

Colouration. Adult. Head pale brown. Antennae with segments 1 and 2 brown, segments 3–8 of a very pale brown, and segments 9 and 10 dark brown tending to black. Thorax mostly dark brown but with medial line crossing mesoscutum and mesopraescutum lighter. Legs with dark brown femora and basal part of tibiae, and with pale brown apical part of tibiae and tarsi (Fig. 8A–D). Fore wings hyaline, with dark brown pattern covering basal 1/3 of wing and reaching wing apex in the basal portion of cell r₂ as a band along posterior wing margin, leaving small transparent areas in cells cu₂, cu₁, m₁ and m₂; dark pattern also covering the proximal part of fore wing, reaching the vein C+Sc, crossing the middle of cell c+sc and the bifurcation of stem R+M+Cu (Figs 8E, F, 9A, B); fore wing veins pale brown or dark brown in areas covered by dark pattern. Hind wing pale to darker brown basally (Fig. 9B). Male and female terminalia pale brown to pale yellow. Female proctiger darker on the tip.

Figure 8.

Pseudophacopteron aewagriini Percy & Martoni, sp. nov. A adult lateral habitus of male B same, female C dorsal habitus of male D same, female E fore wing of male F same, female G immature habitus showing type of truncate marginal setae H metatibiotarsus of immature I circumanal ring of immature. Scale bars: 1 mm (A–D); 0.5 mm (E, F); 0.3 mm (G); 0.1 mm (H, I).

Figure 9.

Pseudophacopteron aewagriini Percy & Martoni, sp. nov. A fore wing of male B fore wing and hind wing of female C detail of radular spinule cluster positions D head (dorsal view) indicating anterior bulges either side of median ridge E head (anterior view) indicating median ridge and genal tubercles below toruli F head (lateral view) indicating protruding genal tubercles G clypeus and proboscis H head and antennae (with detail inset) indicating median ridge on vertex and position of large rhinaria on segments 4–9, termination of two apical setae is indicated by open arrow heads I male (lateral view) J head and thorax (dorsal view) K thorax from dorsal view L thorax from anterior view indicating medial depression on mesoscutum M hind leg with detail of medial constriction of metafemur (inset) N metatibia apex indicating relatively slender lateral setae O metatarsi showing two metabasitarsus spines.

Immature (5^th instar). Body uniformly dark yellow-brown (Fig. 8G).

Structure. Adult. Body relatively small, 1.5–1.9 mm from anterior margin of vertex to tip of folded wings (males smaller than females) (Fig. 8A–D). Head (Figs 8A–D, 9D–F, H–J) in lateral view not deflexed downward and held in same plane as body, wider than thorax but narrower than antennal length, vertex width almost 3 × length, with prominent narrow median ridge and two bulges anteriorly either side of ridge, lateral ocelli raised on small tubercles above the plane of vertex, median epicranial suture reduced. Genae (Fig. 9E, F) small, weakly swollen, genal tubercles below toruli small and acute, prominent in lateral profile. Clypeus (Fig. 9G) subglobular, terminal proboscis segment short. Antenna (Fig. 9H) with ten segments, segment 3 longest with segments 4–8 of subequal length, widening slightly from base to apex, segment 9 slightly shorter and wider apically, while segment 10 very short, < 1/2 the length of segments 3–8 and ~ 1/2 the length of segment 9; a single subapical rhinarium on each of segments 4–9, large, elliptical and fringed by cuticular spines; terminal setae unequal, with longer seta reaching 0.1 mm, shorter seta between 1/2–2/3 length of longer and approx. as long as segments 9 and 10 combined.

Thorax (Fig. 9I–K) moderately arched, mesoscutum with reduced microsculpture and pigmentation in medial depression. Mesotibia with subapical comb of ≤ 6stout setae. Hind legs (Fig. 9M–O) with small, acute and slightly curved meracanthus; metafemur constricted medially, length subequal to metatibia; metatibia without genual spine basally, with an open crown of seven unsclerotised spurs apically and ≤ 12 stout lateral setae more slender than apical spurs; metabasitarsus subglobular, approx. as long as broad, slightly shorter than apical tarsus, with two sclerotised lateral spurs.

Fore wing (Figs 8E, F, 9A, B) elongate, 2.6–2.8 × longer than wide, much wider in apical half, rounded at apex; cell m₁ narrower and more elongate than cell cu₁, vein M approx. as long as vein Rs to the point it meets vein M₁₊₂ and only slightly arched; membrane with dispersed spinules distributed in all cells and with spinule-free bands along veins, radular spinules concentrated into small triangular fields in outer pigmented corners of apical cells cu₁, m₂, m₁, and the adjacent corner of r₂ (Fig. 9C).

Male terminalia (Fig. 10A–C) with subgenital plate subglobular, dorsal margin slightly sinuate and posteriorly bearing several long stout setae; proctiger relatively slender, cylindrical, in lateral profile straight except apex which is slightly bent posteriorly; parameres simple, shorter than proctiger, in lateral profile parallel sided and more or less straight, apex bluntly rounded and slightly bent posteriorly, inner surface with a weakly produced and marginally sclerotized tooth subapically; outer and inner surface covered with fine setae and a few slightly stouter setae subapically. Distal segment of aedeagus relatively short, apical portion ~ 1/3 as long as the distal segment length, somewhat elongate, broadly globular, unhooked but angled downward, apex rounded.

Figure 10.

Pseudophacopteron aewagriini Percy & Martoni, sp. nov. A male terminalia (lateral view) B male terminalia (posterior view) indicating a row of stout setae on dorsal margin C paramere outer surface (left) and inner surface (right), and aedeagus D female terminalia (lateral view) showing irregular profile of anal ring (inset) E ovipositor (lateral view) showing detail of shallow serrations on valvulae dorsalis F female proctiger (dorsal view) with detail of anal ring pores G female subgenital plate (ventral view) indicating truncate and slightly incised apex.

Female terminalia (Fig. 10D–G) with proctiger much longer than subgenital plate, narrowing to bluntly acute apex covered in stout setae, anal ring narrowly oval with the outline in profile and dorsal view irregular, composed of a double row of intermittently irregular pores, anal ring length ~ 1/3 proctiger length; subgential plate ~ 2/3 proctiger length, narrowing to a truncate, weakly incised apex; ovipositor dorsal valvulae triangular, ventral valvulae finely serrate with a series of shallow teeth ventrally.

Immature (5^th instar): body ~ 1.75 × as long as wide, relatively large in size compared to the adult, shape narrowly oval, dorso-ventrally flattened, wing pads not protruding (Fig. 8G). Entire margin of head, wing pads and abdomen ringed with longitudinally ridged, truncate marginal setae with apices raggedly uneven (Fig. 8G). Antenna short, length ~ 0.32–0.45 × head width, with ~ 7 indistinct subdivisions (rhinaria not clearly visible). Fore wing pads lacking distinct humeral lobes, but with slight anterior bulges. Tarsal arolium shorter than claws, membranous, fan-shaped with unguitractor, claws well developed (Fig. 8H). Anus in ventral position (Fig. 8G), circumanal ring shallowly V-shaped, antero-posteriorly constricted and slightly sinuous, consisting of a single row of elongate pores (Fig. 8I).

Measurements (in mm). Adults (5 ♂♂, 5 ♀♀). Length of body (vertex to terminalia) ♂ 1.01–1.17, ♀ 1.22–1.35; length of body (vertex to apex of folded wings) ♂ 1.55–1.80, ♀ 1.78–1.93; width of head (HW) ♂ 0.37–0.42, ♀ 0.40–0.45; length of antenna (AL) ♂ 0.40–0.44, ♀ 0.47–0.51; longer antennal terminal seta length (T1) ♂ 0.06–0.09, ♀ 0.07–0.10; shorter antennal terminal seta length (T2) ♂ 0.03–0.05, ♀ 0.04–0.06; length of antennal segments 9 and 10 together (TS) ♂ 0.05–0.06, ♀ 0.06–0.07; length of fore wing (WL) ♂ 1.27–1.40, ♀ 1.40–1.57; width of fore wing (WW) ♂ 0.45–0.52, ♀ 0.51–0.58; length of line connecting base of vein C+Sc and apex of vein R₁ (CS) ♂ 0.51–0.58, ♀ 0.59–0.65; length of line connecting base of vein C+Sc and costal break (CB) ♂ 0.46–0.52, ♀ 0.51–0.59; length of line connecting the touching point of veins Rs and M₁₊₂ and apex of Rs (a) ♂ 0.17–0.21, ♀ 0.20–0.25; length of line connecting the touching point of veins Rs and M₁₊₂ and apex of M₁₊₂ (b) ♂ 0.41–0.45, ♀ 0.47–0.54; length of line connecting apices of veins Rs and M₁₊₂ (c) ♂ 0.36–0.41, ♀ 0.40–0.48; length of line connecting apices of veins Cu_1a and Cu_1b (d) ♂ 0.34–0.38, ♀ 0.38–0.44; length of line connecting base and apex of vein Cu_1b (e) ♂ 0.12–0.14, ♀ 0.13–0.16; metatibia length (TL) ♂ 0.25–0.31, ♀ 0.28–0.35; male proctiger length (MP) ♂ 0.10; paramere length (PL) ♂ 0.08–0.10; length of distal segment of aedeagus (DL) ♂ 0.08–0.09; female proctiger length (FP) ♀ 0.23–0.27; female subgenital plate length (SL) ♀ 0.14–0.19. Ratios: AL:HW ♂ 1.00–1.19, ♀ 1.13–1.19; T1:TS ♂ 1.20–1.60, ♀ 1.14–1.17; T1:T2 ♂ 1.60–2.00, ♀ 1.50–1.75; WL:HW ♂ 3.28–3.43, ♀ 3.49–3.58; WL:WW ♂ 2.69–2.84, ♀ 2.64–2.80; CB:CS ♂ 0.86–0.91, ♀ 0.86–0.91; a:b ♂ 0.40–0.51, ♀ 0.39–0.52; a:c ♂ 0.45–0.58, ♀ 0.44–0.63; d:e ♂ 2.64–2.83, ♀ 2.56–3.00; TL:HW ♂ 0.68–0.74, ♀ 0.70–0.78; MP:HW ♂ 0.24–0.27; PL:HW ♂ 0.19–0.24; DL:HW ♂ 0.21–0.22; FP:HW ♀ 0.57–0.63; SL:FP ♀ 0.35–0.42.

Immatures (5^th instar, n = 4). Length of body 1.50–1.60; width of body 0.88–0.96; length of antennae 0.17–0.25; width of head 0.54–0.56.

Etymology.

The name epithet uses the Norf’k (local resident language spoken on Norfolk Island) word “aewagriin” that refers to the host plant, Alyxia gynopogon, known on Norfolk Island as the Evergreen. The name is treated as a Latinised noun, gender masculine, in genitive case. This name was chosen by receiving multiple nominations during the Norfolk Island Flora and Fauna Society meeting, held on Norfolk Island on the 10 June 2023. Members of the society remarked on the importance of such a species that has managed to “hairng orn” (hold its place) on Norfolk Island.

Distribution.

This species is the only Pseudophacopteron present on Norfolk Island, and has been recorded from locations throughout Norfolk Island National Park (Fig. 15). The species has also been recorded within Selwyn Reserve, a Norfolk Island Regional Council reserve which adjoins the western border of the National Park (G. Maynard, pers. comm. 2024; Fig. 15). The distribution of this species is limited by the distribution of the host plant, which although common within the National Park, is scarce across the rest of the island group. No specimens have been found on the few plants that have been located and inspected outside of the National Park and Selwyn Reserve and it is likely P. aewagriini is confined to the National Park and its immediate surrounds.

Host plant on Norfolk Island.

Alyxia gynopogon Roem. & Schuit. (Gentianales, Apocynaceae).

Conservation.

This species is considered endemic to Norfolk Island, as is its host plant, Alyxia gynopogon. The host is not currently regarded as threatened, however, it is almost entirely confined to Norfolk Island National Park, with only scattered specimens known from other areas of the island. Neither species is known from nearby Phillip Island. Despite searching, P. aewagriini is known only from the National Park and the adjoining Selwyn Reserve, meaning the EOO ranges from 1.3–6.8 km², based on either confirmed occurrence records, or the entire area of the National Park, Botanic Gardens, and Selwyn Reserve (Fig. 15). The corresponding AOO calculated using a 4 km² grid overlay, ranges from 16–20 km². The range reduction suffered by this species following European colonisation is likely to have ceased in 1984 following the establishment of the National Park. It is likely that A. gynopogon and P. aewagriini increased in range slightly following the cessation of grazing by cattle within the National Park. The species is not known to be undergoing a population or range decline, nor is it known to be facing any ongoing threats. However, Norfolk Island National Park and Selwyn Reserve have been identified as being highly vulnerable to wildfire under optimal fire conditions which could destroy a large proportion of the habitat for P. aewagriini, particularly given Norfolk Island’s ecosystems are not fire-adapted (Eco Logical Australia 2021). Predicted drying of Norfolk Island’s climate (Petheram et al. 2020) exacerbates the risk of wildfire, and may also reduce the quality of the rainforest inhabited by this species and its host plant. Invasive Argentine ants (Linepithema humile) are established on the island and although they are subject to an extensive control and eradication effort (NIRC 2021) their spread into the National Park could impact P. aewagriini populations.

We propose that P. aewagriini warrants a threat classification of Vulnerable under criterion D2 (IUCN 2012). This species is known from only a single location but is not currently known or suspected to be undergoing continuing decline or extreme fluctuation in its range or population size. However, it has an EOO of 16–20 km² and plausible future threats in the form of wildfire which could destroy much of its habitat, ongoing reduction of habitat quality due to predicted climate drying, and Argentine ant invasion. As such, this species could quickly be driven to Critically Endangered under Criteria B if these threats were to materialise (IUCN 2012). Consideration should be given to establishing populations of A. gynopogon and P. aewagriini in other areas of Norfolk Island, as well as on nearby Phillip Island, to increase the security of both species.

DNA resources.

GenBank COI: MG988815, MG988814, cytB: MG989134, MG989135. Also represented in the mitogenome analysis of Percy et al. (2018) as: DP1.idba.137, and the annotated mitochondrial genome is in GenBank: MG989234 (Percy et al. 2018; see also Fig. 16). Additionally, a total of four COI sequences were generated for this study (OR558312–OR558315; Table 1).

Systematics.

This species may be related to Pseudophacopteron tuberculatum (Crawford, 1912) which is native to China, southeast Asia, and Papua New Guinea (PNG) and induces closed galls on the leaves of Alstonia (Apocynaceae; Percy et al. 2016; Luo et al. 2018), the same plant family as Alyxia. Although Luo et al. (2018) noted that there are no morphological characters suggesting that all Pseudophacopteron species developing on Apocynaceae constitute a monophyletic group, the molecular data do support P. aewagriini from Norfolk Island and P. tuberculatum (COI GenBank sample MH769661) as likely being in the same clade. Unfortunately, the backbone analysis currently involves inclusion of more short (and non-overlapping) sequences than there are taxa in the original mitogenome data, which makes a rigorous backbone analysis not possible at this time. Morphologically, there are some shared traits with two species described from Brazil, P. aspidospermi Malenovský et al., 2015 and P. longicaudatum Malenovský et al., 2015, which produce closed leaf galls on Aspidosperma (Apocynaceae) (Malenovský et al. 2015); but overall, more systematic data on this group in the Austro-Pacific region are needed for conclusions to be made.

Remarks.

This species is the first described Pseudophacopteron species known to be associated with Alyxia (Apocynaceae). The related Pseudophacopteron tuberculatum is considered a serious pest of plantations of Alstonia scholaris (Apocynaceae) in the Philippines (Braza and Calilung 1981). The host plant of P. aewagriini, Alyxia gynopogon, is a Norfolk Island endemic, evergreen understory shrub, which is relatively common within the National Park. The galling of leaves by P. aewagriini, inducing the characteristic open pit galls on the leaves (Fig. 7A–C), does not appear to be overly detrimental to the host. Hollis (2004) and Malenovský (2008) reported the presence of an unnamed species of Pseudophacopteron on Lord Howe Island, where there are three species of Alyxia: the endemic A. lindii and A. squamulosa, and the native A. ruscifolia. A number of Pseudophacopteron species associated with Alyxia, not yet formally described, have been reported from Western Australia (iNaturalist observation 138485676), Queensland (Malenovský 2008, iNaturalist observation 154392985) and South Australia (G.S. Taylor, pers. comm. 2023). Informal descriptions of two of these species were included in the PhD thesis of Malenovský (2008). These two species are close to Pseudophacopteron aewagriini and all three species belong to the same “narrow-winged” clade identified by Malenovský (2008), which also includes a Pseudophacopteron sp. from Papua New Guinea, another species from both Papua New Guinea and Sulawesi, and a third species from Costa Rica (Malenovský 2008). Malenovský (2008) also noted that the two species from Queensland and Lord Howe Island can be separated from the remaining taxa in the “narrow-winged” clade by the presence of a distinct median ridge and anterior bulges or tubercles on the vertex, and these characteristics are shared with P. aewagriini (Fig. 9D, E, H). Pseudophacopteron aewagriini can be differentiated from the undescribed taxa occurring in Queensland and Lord Howe Island in the relative length of the paired apical antennal setae, with the two undescribed species showing these setae to be of similar or slightly unequal length, while in P. aewagriini the shorter seta is between 1/2–2/3 length of the longest seta (Fig. 9H). The fore wing of P. aewagriini is distinct in appearing intermediate between the two undescribed species. The overall fore wing structure and shape of P. aewagriini is more similar to the Queensland species but is less narrow as in the Lord Howe Island species. The basal fore wing markings are more similar to that of the Lord Howe Island taxon, without a distinct unpigmented area alongside vein M+Cu, but more similar to the Queensland taxon in the marginal fore wing markings which have larger unpigmented spots in cells cu₁, m₁ and m₂. The extent of marginal pigmentation in cell r₂ is reduced in P. aewagriini compared to either of the undescribed Australian species. Additionally, P. aewagriini shares the seven unsclerotised apical spurs on the metatibia with the Lord Howe Island taxon, versus 11 in the Queensland taxon.

Subfamily Spondyliaspidinae

Blastopsylla occidentalis Taylor, 1985

Fig. 11A

Distribution. Native to Australia (Taylor 1985) and previously reported on Norfolk Island (Maynard et al. 2018). Present also in the Americas – Argentina (Bouvet et al. 2005), Brazil (Burckhardt et al. 1999), Chile (Burckhardt and Elgueta 2000), Mexico (Hodkinson 1991), Nicaragua (Queiroz et al. 2018), United States of America (California – Taylor 1985; Florida – Halbert et al. 2001), Uruguay (Martínez et al. 2014); Africa – Burundi (Queiroz et al. 2018), Cameroon (Dzokou et al. 2009), Egypt (El Nasr and Abd-Rabou 2012), Kenya (Hollis 2004), South Africa (Neser and Millar 2007); Asia – China (Hollis 2004), Indonesia (Borneo – Burckhardt et al. 2024; Sumatra – Queiroz et al. 2018), Israel (Spodek et al. 2015), Philippines, Turkey (Drohojowska and Burckhardt 2014), Yemen (Queiroz et al. 2018); Europe – Cyprus (Demetriou et al. 2022), Italy (Laudonia 2006), Malta (Mifsud and Carapezza 2020), Portugal, Spain (Pérez-Otero et al. 2011); Oceania – New Zealand (Dale 1985).

Host plant on Norfolk Island. Eucalyptus botryoides Sm. (Myrtales, Myrtaceae), confirmed by the collection of immatures (Suppl. material 1).

Remarks. Adventive to Norfolk Island (Maynard et al. 2018). Immature stages are free-living.

Cardiaspina fiscella Taylor, 1962

Fig. 11B

Figure 11.

Lateral habitus (all female except where noted) A Blastopsylla occidentalis B Cardiaspina fiscella C Cryptoneossa triangula D Glycaspis granulata E Mesohomotoma hibisci (male) F Acizzia acaciaebaileyanae G Acizzia hakeae H Acizzia sp. B I Acizzia sp. A J Heteropsylla cubana K Bactericera cockerelli L Powellia vitreoradiata. Scale bars: 1 mm.

Distribution. Native to Australia (Taylor 1962) and previously reported on Norfolk Island (Maynard et al. 2018). Present also in New Zealand (Henderson et al. 2010)

Host plant on Norfolk Island. Eucalyptus botryoides (Myrtales, Myrtaceae). No immature specimen was collected (Suppl. material 1), but lerps were observed (Fig. 7D).

Remarks. Adventive to Norfolk Island (Maynard et al. 2018). The immatures of this species are known to build lerps (Taylor 1962), and these were recorded on Norfolk Island (Fig. 7D).

Cryptoneossa triangula Taylor, 1990

Fig. 11C

Distribution. Native to Australia (Taylor 1990). Present in New Zealand (Henderson et al. 2010) and United States of America (California – Gill 1995, Brennan et al. 1999; Oregon – Castillo Carrillo et al. 2016).

Host plant on Norfolk Island. Eucalyptus sp. (Myrtales, Myrtaceae).

Remarks. First report from Norfolk Island, where it is considered adventive. The immatures of this species are free-living, but no immature specimen was collected on Norfolk Island.

Glycaspis (Glycaspis) granulata (Froggatt, 1901)

Fig. 11D

Spondyliaspis granulata Froggatt, 1901: 293.

Glycaspis granulata ; Taylor 1960: 385.

Glycaspis (Alloglycaspis) granulata; Moore 1961: 164–165.

Glycaspis (Glycaspis) granulata; Moore 1970: 308.

Distribution. Native to Australia (Froggatt 1901) and previously reported on Norfolk Island (Maynard et al. 2018). Present in New Zealand (Withers 2001).

Host plant on Norfolk Island. Eucalyptus sp. (Myrtales, Myrtaceae).

Remarks. Adventive to Norfolk Island (Maynard et al. 2018). The immatures of this species are known to build square-shaped white lerps (Moore 1970), although no lerps were observed on the island during the collection of the specimens.

Family Carsidaridae

Subfamily Carsidarinae

Mesohomotoma hibisci (Froggatt, 1901)

Fig. 11E

Tyora hibisci Froggatt, 1901: 287.

Udamostigma hibisci ; Enderlein 1910: 138.

Mesohomotoma hibisci ; Crawford 1920: 356.

Distribution. Originally described from Australia (Froggatt 1901) and previously reported on Norfolk Island (Maynard et al. 2018). Present in Oceania – Bismarck Archipelago, Caroline Islands, Cook Islands, Fiji (Hodkinson 1983), French Polynesia (including Marquesas – Hollis 1987, Society and Austral Islands – Hodkinson 1983), Gilbert Islands, New Caledonia, Palau, Solomon Islands, Tonga, Vanuatu (Hodkinson 1983); Africa – Cameroon (Yana et al. 2015), Democratic Republic of the Congo, Kenya, Madagascar, Mauritius, Seychelles, South Africa, Tanzania, Uganda, Zimbabwe (Burckhardt and van Harten 2006); Asia – Chagos Archipelago (Hodkinson 1983), China (Hong Kong – Hodkinson 1986), India, Indonesia (Burckhardt and van Harten 2006; including Borneo – Hodkinson 1983), Japan (Kyushu – Hodkinson 1983; Ryukyu Islands – Burckhardt and van Harten 2006), Laos (Cho et al. 2017), Malayasia (peninsula – Hodkinson 1983, 1986; Sabah – Cho et al. 2017), Philippines (Burckhardt and van Harten 2006, including Luzon– Hodkinson 1983), Singapore (Percy 2017), Thailand (Cho et al. 2017), Yemen (Burckhardt and Van Harten 2006).

Host plant on Norfolk Island. Hibiscus tiliaceus L. (Malvales, Malvaceae), confirmed by the record of immatures (Suppl. material 1).

Remarks. The immatures of this species congregate on the underside of leaves and in the folded new leaf growth, producing copious amounts of flocculent material (Froggatt 1901; Fig. 7E). We consider M. hibisci to be native to Norfolk Island based on the widespread distribution of its host plant, Hibiscus tiliaceus, in the Pacific. However, the native status of H. tiliaceus on some Pacific islands has been debated as it is one of several “tramp” species in the Pacific that was used by Polynesians for medicinal purposes (Lim 2014) and therefore may have been transported between islands. Polynesians are known to have inhabited Norfolk Island 600–800 years ago but were not present at the time of European settlement (Anderson and White 2001). It can therefore not be ruled out that both host, H. tiliaceus, and psyllid, M. hibisci, were introduced to Norfolk Island by early Polynesian settlers.

Family Psyllidae

Subfamily Acizzinae

Acizzia acaciaebaileyanae (Froggatt, 1901)

Fig. 11F

Psylla acaciaebaileyanae Froggatt, 1901: 257.

Arytaina acaciaebaileyanae ; Pettey 1924: 21.

Psylla uncata Ferris & Klyver, 1932: 53; Tuthill 1952: 91.

Neopsylla uncata ; Heslop-Harrison 1949: 162.

Psylla (Acizzia) acaciaebaileyanae; Tuthill 1952: 91.

Acizzia acaciaebaileyanae ; Capener 1970: 197.

Distribution. Native to Australia (Froggatt 1901). Present in Africa – South Africa (Pettey 1924); Europe – Croatia (Pintar et al. 2021), France (Malausa et al. 1997), Germany (Burckhardt and Lauterer 2003), Great Britain (Malumphy and Luker 2014), Italy (Rapisarda 1985), Netherlands (Suh and Choi 2020), Poland (Seljak et al. 2004), Slovenia (Seljak 2006); Oceania – New Zealand (Ferris and Klyver 1932); Asia – Philippines (Hodkinson 1983); America – United States of America (California – Gill 1987).

Host plant on Norfolk Island. Acacia podalyriifolia A.Cunn. ex G.Don (Fabales, Fabaceae), confirmed by the record of immatures (Suppl. material 1).

Remarks. First report from Norfolk Island. Acacia podalyriifolia, a popular garden ornamental, was not recorded as being present on the island by Green (1994) but was certainly present by 2010 (Wilcox et al. 2010), suggesting both it and Acizzia acaciaebaileyanae may have reached Norfolk in the intervening 16 years.