Three new species of gall-forming psyllids (Hemiptera: Psylloidea) from Papua New Guinea, with new records and notes on related species

ABSTRACT Three new species of gall-forming psyllids (Hemiptera: Psylloidea) in the families Triozidae and Phacopteronidae are described from Papua New Guinea: Trioza incrustata Percy, sp. nov. makes enclosed leaf margin galls on Celtis philippensis (Cannabaceae), Trioza grallata Percy, sp. nov. makes enclosed leaf surface galls on Elaeocarpus schlechterianus (Elaeocarpaceae), and Cornegenapsylla allophyli Malenovský and Percy, sp. nov. makes enclosed leaf margin galls on Allophylus cobbe (Sapindaceae). Descriptions of the adult and immature morphology for these new species are provided, and differences in adult and immature morphology between Cornegenapsylla allophyli and Cornegenapsylla sinica Yang and Li, 1982 (the type species of Cornegenapsylla) are illustrated. We report new records for Papua New Guinea of Pseudophacopteron tuberculatum (Crawford, 1912) on Alstonia sp. (Apocynaceae), Pauropsylla triozoptera Crawford, 1913 on Ficus trachypison (Moraceae) and Pauropsylla udei Rübsaamen, 1899 on Ficus variegata, with descriptions of the variation found in the latter two widespread Asian species. Pauropsylla reticulata Mathur, 1975 is synonymized with P. udei. Mitochondrial DNA barcodes for the new species, as well as for P. triozoptera and P. udei are provided.


Introduction
The diversity, distribution and taxonomic placement of gall-inducing taxa among psyllid families has been reviewed by Hodkinson (1984Hodkinson ( , 2009, Burckhardt (2005), Yang et al. (2006), and Yang and Raman (2007). There is no well-established estimate of the number of galling psyllid species worldwide, although a higher percentage of galling species is known to occur in particular psyllid families, e.g. Triozidae, Phacopteronidae and Calophyidae (Burckhardt 2005;Malenovský et al. 2007;Yang and Raman 2007), and in geographic distribution, e.g. higher rates of galling in the tropics, and particularly in South East Asia and the Pacific (Hodkinson 1983;Burckhardt 2005). Numbers of galling psyllids may be equally as high in Afrotropical and Neoptropical regions but these faunas are poorly known (D. Burckhardt pers. comm.). Confounding factors affecting attempts to estimate the number of galling species include poorly resolved taxonomies, large numbers of species still needing to be described particularly from the tropics, and uncertain associations between gall types and particular psyllid taxa, e.g. those listed as 'undertermined psyllid galls' in Hodkinson (1983). In other cases, general leaf distortion through feeding has been considered a gall by some but not others; while some psyllid taxa make one type of gall, such as a pit gall, as an early instar and another type of gall, such as a leaf roll or enclosed leaf gall, as a later instar. Furthermore, although some taxa have been established as root gallers, little is known about the extent of this type of galling habit (Lauterer and Baudyš 1968;Bird and Hodkinson 1999). The majority of psyllid gall types, however, are produced on the leaves of plants, e.g.~75% of galling species in Taiwan (Yang et al. 2006). In other regional faunas where the native psyllid fauna has been relatively well studied, galling species may make up less than 15% (e.g. UK) of the total psyllid fauna in temperate zones, and more than 50% (e.g. Hawaiian Islands) in the tropics (Zimmerman 1948;Hodkinson 2009). In Taiwan,~100 species of gallers represent 60% of the described psyllid fauna (Yang and Raman 2007), and in Japan~45 species of gallers represents~50% of the described fauna (Yukawa and Masuda 1996). Notably, both of these oriental galling faunas are dominated by taxa in the family Triozidae (Yukawa and Masuda 1996;Yang and Raman 2007;Yang et al. 2013).
The psyllid fauna of Papua New Guinea (PNG) is poorly known, with only 15 species recorded (Ouvrard 2015), but it may be reasonable to expect a ratio of galling to non-galling taxa similar to that found in other oriental faunas, as well as a similar dominance of Triozidae among the gallers. The species treated here were mostly collected by P.T.B. during ecological surveys of galling insects from lowland and montane rainforests in Madang and Morobe Provinces, PNG, in association with the New Guinea Binatang Research Centre (http://www.entu.cas.cz/png/parataxoweb. htm). Three new species are described, two in the family Triozidae and one in Phacopteronidae, and the taxonomy of Cornegenapsylla sinica Yang and Li, 1982 (Phacopteronidae) is reviewed. Cornegenapsylla was a previously monotypic genus containing the longan psyllid (Cornegenapsylla sinica), which is widespread in Asia, including China, Malaysia and Thailand (Yang and Li 1982;Hodkinson 1986;Martin and Lau 2011), and new records from Singapore are reported here. We also report new records for PNG of Pauropsylla triozoptera Crawford, 1913 on Ficus trachypison (Moraceae) and of Pauropsylla udei Rübsaamen, 1899 on Ficus variegata with description of the variation found in the PNG specimens and galls relative to specimens from elsewhere (Hong Kong, Bangladesh, Philippines) for these widespread Asian species; we synonymize Pauropsylla reticulata Mathur, 1975 with P. udei; and we report new records for PNG of Pseudophacopteron tuberculatum (Crawford, 1912) on Alstonia sp. (Apocynaceae). We include mitochondrial DNA barcodes for the new species, as well as for P. triozoptera and P. udei to provide an estimation of mitochondrial genetic distances between these taxa.

Material and methods
Lowland field collections were made in the period August 2010 to March 2011 (with a few samples dating back to 1995 and 1996) near the villages of Baitabag, Mis and Ohu, Madang Province, PNG, which are each surrounded by approximately 200 ha of mixed secondary and primary rainforest. Further collections were made in montane rainforest in the period August 2010 to November 2012 near Yawan village in the Finisterre Range of mountains, Morobe Province. Adults were reared from galls placed in clear plastic bags and pegged to washing lines in open-sided barns, and immatures were dissected from galls in the field on an ad hoc basis. Adults and immatures were preserved in 95% ethanol.
Adult structure Forewings ( Figure 1A) long and narrow with acutely pointed apex, cell cu 1 distinctly larger than cell m 2 , vein Rs short, curving to the wing margin; a group of marginal radular spines present in cells cu 1 , m 1 and m 2 ; surface spinules sparsely scattered in all cells; wing margins and veins sparsely covered with short to minute setae. Head not strongly deflexed with genal processes short, divergent and conical, more or less symmetrical and broadly rounded at apex ( Figure 1C). Vertex more or less flat dorsally, with lateral ocelli lying on small tubercles, medial epicranial suture distinct. Antennae ( Figure 1B) long and slender, 3rd antennal segment 0.6 × head width, 10-segmented with rhinaria apically on segments 4, 6, 8 and 9, terminal segment with one apical seta medium long (~0.05 mm), paired with a short blunt tube-like seta (less than half the length,~0.02 mm). Clypeus ( Figure 1D) triangular in lateral view, bearing two medium long setae apically. Distal segment of proboscis medium long. Dorsum of thorax with scattered short setae. Hind leg ( Figure 1G) with meracanthus well developed and straight; metatibia with a single large genual spine basally and 1+3 (typically) or 1+2 shortly stalked sclerotized apical spurs; metabasitarsus constricted medially and longer than apical tarsus. Male terminalia ( Figure 1H) with proctiger lobed basally; paramere ( Figure 1I) expanded basally into a distinct internal bulge and then tapering evenly to a darkly sclerotized apex; apical aedeagus segment ( Figure 1J) short, hooked and with an extended, sharply pointed beak. Female terminalia ( Figure 1K) short, proctiger curving downwards and slightly longer than the bluntly terminating subgenital plate, circumanal ring relatively large, 0.36 × length of proctiger, and composed of a double row of cells; ovipositor valvulae dorsales ( Figure 1L) in profile with medial bulge dorsally.
Adult measurements (mm) and ratios (

Immature structure
Body outline elongate ovoid and more or less uninterrupted (Figure 2A, E, F). Forewing buds with pronounced humeral lobe. Antennae of 5th instar ( Figure 2C) with seven or eight segments bearing four rhinaria, one each apically on segments 3 and 5 and two on the terminal segment; 4th instar antennae 3-or 4-segmented bearing one rhinarium on 3rd segment, and two rhinaria on terminal 4th segment; 3rd instar antennae 3-segmented bearing one rhinarium on 2nd segment and one on terminal 3rd segment; 2nd instar antennae 1-segmented bearing one rhinarium. Tarsi with well-developed claws and crescent arolia ( Figure 2C). Distinct 'thoracic lobes' visible in 5th instar (see inset Figure 2A). Anus situated ventrally; circumanal ring broad and shallowly V-shaped, with a single row of elongate cells.

Immature chaetotaxy
The 2nd-5th instars with stalked, fan-shaped setae around the margin ( Figure 2B, F), 3rd-5th instars with dorsal surface covered in distinct pattern created by the arrangement of simple setae on round tubercle-like annuli (

Biology
The gall is a leaf fold at the margin of the leaf and consists of the upper adaxial surface folding down to make the gall on the lower abaxial leaf surface ( Figure 3A). The fold becomes sealed and appears to contain a single immature. There is sometimes a single fold, but more often several discrete chambers, in this case, it is not clear whether each chamber is completely sealed from the others. When mature, the gall seal opens along the intersection between adaxial and abaxial leaf surfaces. The density of galls and immatures is high with~70 immatures collected from three sample sites. Rearing from galls produced five adult psyllids from two of these sites. Other insect associates found in the galls include cecidomyid larvae, and chalcid pupae and larvae (Encyrtidae and Eulophidae).

Etymology
The specific epithet refers to the distinct pattern on the dorsum of older immatures appearing as an encrustation formed by the tubercle-like annuli at the base of the setae. Perfect passive participle derived from the Latin verb incrustare, to have an ornamental cover.

Comments
The host plant is a common lowland rainforest tree in New Guinea and much of South East Asia (George Weiblen, pers. comm.). Six additional triozid taxa are known from the plant genus Celtis. Yang (1984) described two of these species from Taiwan, Trioza celtisae Yang, 1984 and Trioza lineata Yang, 1984 on Celtis tetrandra and Celtis sinensis, respectively. Li (2011) described an additional species from Celtis sinensis, Trioza longigenitus (Li 2011), and the immatures and biology for Trioza bifasciaticeltis Li and Yang, 1991, which has free-living immatures on the lower abaxial surface of leaves. Although no biology is mentioned for the immatures of T. celtisae, this species is related to T. lineata, which is also described as having free-living immatures on the lower abaxial surface of leaves (Yang 1984). Li (2011) placed the above species in a new genus, Metatriozidus, but this was considered artificial and synonymized with Trioza by Yang et al. (2013). A fifth Asian species, Trioza brevifrons Kuwayama, 1910, is recorded from Korea, Japan and Taiwan. The host-plant in Korea and Japan is Celtis sinensis var. japonica (Kwon 1983), but the host association of the type material from Taiwan is unknown, and these specimens appear to differ from those in Korea and Japan (Kwon 1983;Yang et al. 2013). Lastly, a South American species, Leuronota fuscata (Laing, 1923) develops on Celtis iguanaea (Burckhardt and Queiroz 2012, and D. Burckhardt pers. comm.). None of these Celtis-feeding triozid species appears related to Trioza incrustata sp. nov., and no clear affiliations are apparent within the Triozidae; we therefore place this taxon within the artificially large (polyphyletic) genus Trioza Foerster, 1848. Trioza incrustata is the first species of Trioza known to produce leaf margin galls on Celtis.
Adult colour (ethanol material) Forewings without pattern but membrane fuscous, veins brown. Body generally mid to dark brown, with distinct pale longitudinal band on the dorsum of the thorax ( Figure 4E) and sometimes extending forward through the vertex. Ventral part of the abdomen, particularly in females, may also be paler. Antennal segments 3-10 dark brown to black. Legs paler except apices of tibiae and tarsi, which are dark brown to black.
Adult structure Forewings ( Figure 4A) distinctly broader in the apical half with a bluntly acute apex; height of cells cu 1 and m 2 subequal; vein Rs short, curving evenly to the wing margin; a group of marginal radular spines present in cells cu 1 , m 1 and m 2 ; surface spinules either absent or very sparsely distributed; wing margins and veins with short to minute setae. Head ( Figure 4G) with genal processes short, widely divergent, asymmetrical, and terminating in slightly swollen, blunt apices with two or three long stout setae; distinct swellings also present below the genae ( Figure 4H). Vertex more or less flat dorsally, with lateral ocelli lying on small tubercles, medial epicranial suture distinct. Antennae ( Figure 4G) long and slender, 3rd antennal segment 0.75-0.81 × head width, 10-segmented with rhinaria apically on segments 4, 6, 8 and 9, terminal segment with one long apical seta (0.09-0.12 mm), paired with a short stout tube-like seta (less than half the length,~0.02 mm). Clypeus ( Figure 4I) well rounded and ventrally scaly, rough surfaced, and covered in short setae plus two long setae. Distal segment of proboscis medium long. Dorsum of thorax covered in short, stout setae. Hind leg ( Figure 4F) with meracanthus well developed and straight; metatibia slender and elongate (almost twice the length of the metafemur), with one, but more usually a pair of genual spines basally and 1+3 (occasionally 1+4) large, distinctly stalked and sclerotized apical spurs; metabasitarsus constricted basally and subequal in length to apical tarsus. Sternites with numerous stout setae ( Figure 4J). Male terminalia ( Figure 4K) with proctiger strongly lobed medially and constricted to a narrow tube dorsally. Paramere ( Figure 4L, M) expanded into a lobe in the basal half and then more or less parallel sided and slightly arched backwards, the posterior margin with a comb of long stout setae, and terminating in a small posteriorly directed sclerotized hook. Apical aedeagus segment ( Figure 4O) short, base swollen, strongly curved basally and then angled apically, with a rounded and slightly inflated apex. Female terminalia ( Figure 4P) with proctiger more or less straight dorsally, ventral margins lobed medially; apex acute, darker, and covered in short stout setae; proctiger markedly longer than (> 1.5 ×) the bluntly terminating subgenital plate, apex of subgenital plate notched and terminating in several long setae; circumanal ring ( Figure 4Q) is long and narrow, 0.3 × the length of proctiger, and composed of a double row of cells; inner ovipositor valve ( Figure 4R) small and in profile slightly bulging dorsally.

Immature chaetotaxy
The 1st-5th instars have scattered medium to long simple setae on margins and surfaces of head, thorax, and abdomen; in addition, the 5th instar also has irregular patches of short, stout, thorn-like cuticular projections on the dorsal surface of the abdomen ( Figure 2G).

Biology
This species produces small, round to ovoid, enclosed blister-like galls on the leaf blade ( Figure 3C), which are exited mostly on the upper adaxial leaf surface. In all galls dissected (n = 13), there was a single unilocular gall chamber, and when present, a single immature psyllid. Incubating galls for rearing produced~90 adult psyllids. Associated insects included cecidomyid and sciarid midges, and chalcid parasitoids.

Etymology
The specific epithet refers to the long, slender tibiae, hence from the Latin gralla, a stilt, grallata = bearing stilts (adjective).

Comments
The host plant is a New Guinea endemic known from rather few collections, at elevations of 850-1850 m, from Jayapura (Papua) through the highlands to Morobe Province.
(George Weiblen pers. comm., with reference to Coode 1981). Five species of Trioza are known from the plant genus Elaeocarpus. Matsumoto (1999) treated three of these, together with two additional species that may also be Elaeocarpus-feeders, as the 'Trioza maculata group'. The maculata group is found in Japan, Taiwan, Vietnam and Malaysia (Sabah). Trioza grallata sp. nov., on Elaeocarpus schlechterianus, does not appear to be related to this group. Neither does it appear to be related to either of the two remaining species known from Elaeocarpus that both produce small galls on the leaves. One of these species, from Taiwan, Trioza elaeocarpi Yang, 1984, produces small round galls on leaves of Elaeocarpus sylvestris (Yang 1984), and the other, Trioza indigena Tuthill, 1951, from the Caroline Islands forms small leaf galls on Elaeocarpus kusanoi, which is endemic to the island of Pohnpei, Senyavin Islands (Tuthill 1951

Comments
This species is widespread in eastern Asia. We report the first records for PNG, Madang Province, on Ficus trachypison (Moraceae). All known Pauropsylla are gall inducing. This species shares with Pauropsylla udei a galling habit on Ficus in PNG, but there are notable morphological differences between the two species, including the male terminalia illustrated in Figure 5(G, I); the head structure (illustrated by Uichanco 1921); antennae with three rhinaria on segment 3 and a single rhinarium on segments 4, 6, 8 and 9 (the latter associated with a very long seta as long as segment 10) in P. triozoptera, versus only four on segments 4, 6, 8 and 9 (associated with a short seta) in P. udei; metatibia with three apical spurs in P. triozoptera versus four (2 + 2) in P. udei, and the female terminalia. The immatures can also be differentiated primarily by the large distinctly shaped circumanal pore area in P. triozoptera ( Figure 6H, and illustrated by Yang 1984) versus much reduced anus lacking circumanal pore area in P. udei. Genetic divergence between the two species is high (mitochondrial DNA divergence > 20%).

Biology
Dissected galls from PNG (on F. trachypison) and from Taiwan (on F. cf. ampelas) contained a single immature per gall. As described below for P. udei, some noticeable variation in gall phenotype within this species was found. All galls produced by P. triozoptera are enclosed galls on the leaf blade, but in PNG the gall exterior is covered in spine-like trichomes, whereas in Taiwan the galls are smooth, without trichomes ( Figure 3F). Furthermore, the shape of the galls in Taiwan is narrowly conical, and in PNG it is globular or broadly conical (bell-shaped), produced on the upper adaxial leaf surface; on some leaves from PNG, mature galls appear to fuse, forming an irregular bumpy mass in which individual galls are difficult to distinguish. In PNG, the galls on   hainanensis in China (Yunnan) (Li et al. 2000). In Taiwan, a 5th instar was found parasitized by Psyllaephagus sp. (Encyrtidae, det. J. Noyes, BMNH).

Comments
This species is widespread in Asia. We report new records for PNG, Madang Province, on Ficus variegata (Moraceae), and illustrate some of the variation found in the structure of the male terminalia from different parts of the Oriental Region ( Figure 5I). The PNG specimens have a narrower male paramere and proctiger, and the female terminalia are shorter, but otherwise specimens are similar to those examined from Hong Kong and Bangladesh; specimens from the Philippines show the most structural difference in male terminalia and further investigation of regional patterns of intra-specific variation is needed to assess whether there is sufficient divergence to warrant recognizing separate species. The 2nd and 5th instar immatures from PNG are covered in medium to long simple setae as illustrated in Rübsaamen (1899). Immatures examined from Sarawak and Hong Kong did not reveal noticeable differences. Genetic divergence between PNG and Singapore specimens supports the need for further intra-specific investigation (mitochondrial DNA divergence was relatively high,~10%), as does the striking gall type differences between PNG and other areas.

Comments on synonymization
Nine adult specimens of P. reticulata Mathur, 1975 collected together with the type series at the type locality, together with two dried galls, were sent to BMNH in 1931 (Mathur 1975). The suspected synonymy of this material was noted by Hollis (1984, p. 28), and after examining this material, DMP concurs with his assessment and the synonymy is formalized here. The two galls are spherical and globular, and appear similar to those found on Ficus variegata (Moraceae) from Singapore ( Figure 5E) and the Philippines (illustrated by Uichanco 1919), but they appear to lack exterior trichomes. In addition, there is some uncertainty regarding the host-plant range, as the holotype and paratype series (including BMNH material) was collected 'ex galls on unknown plant', but Mathur (1975) also cites other material collected from West Bengal, India (13 July 1935) ex galls on leaves of Breonia chinensis (= Anthocephalus indicus; Rubiaceae) in his description of P. reticulata. Furthermore, the type series of P. udei was originally described with the host as an unknown species of Rubiaceae in Sumatra, which was subsequently considered a host record error by Uichanco (1921), and certainly the original illustration and description of the galls by Rübsaamen (1899) for P. udei resemble closely those illustrated here on Ficus variegata leaves ( Figure 5E).

Biology
As noted for P. triozoptera above, we report notable variation in the gall phenotype. In all cases, the galls of P. udei are enclosed and produced on the leaf blade. In PNG the galls are conical and smooth, without trichomes, and produced on the lower, abaxial leaf surface ( Figure 3D). Those found in the Philippines, Singapore and Hong Kong are spherical or oval, usually produced on the upper, adaxial leaf surface, and the outer surface of each gall is covered in trichomes that are cream to red; gall coverage can be dense on younger leaves ( Figure 3E).
Adult structure Forewing ( Figure 6A) with apex broadly truncate; cell cu 1 small; membrane lacking surface spinules, but with small patches of radular spines close to veins at the margin. Head distinctly wider than thorax. Vertex ( Figure 6G) almost flat dorsally, with lateral ocelli lying on small tubercles, rounded down to frons; medial epicranial suture distinct anteriorly and posteriorly, but indistinct medially. Genae very small, weakly swollen, with a small tubercle below insertion of antennae ( Figure 6G). Antenna ( Figure 6E) relatively long; the 3rd segment strikingly enlarged, approximately as long as segments 4 and 5 together; segments 4-10 slender; segments 4-9 each with widely elliptic rhinarium largely bordered with wreath of small, acute cuticular spines, segments 4-8 each with an additional sensilla lying in a transverse groove closely adjacent to rhinarium ( Figure 6F); terminal setae subequal, slightly shorter than segments 9 and 10 together ( Figure 6E). Clypeus ( Figure 6D) somewhat flattened, rounded at apex, lacking long setae. Apical segment of proboscis short. Metatibia with a small genual spine basally, and 13-15 evenly sized unsclerotized spurs apically; metabasitarsus slightly longer than apical tarsal segment and bearing two sclerotized lateral spurs ( Figure 6B). Male subgenital plate elongate, strongly produced into a posterior hump ( Figure 6H). Male proctiger ( Figure 6H) narrowly conical. Paramere ( Figure 6I) curved posteriorly, with apex broadly rounded; inner side covered with fine setae. Distal segment of aedeagus ( Figure 6J) with a rounded, unhooked apex. Female terminalia ( Figure 6K) long; proctiger with dorsal margin nearly straight; circumanal ring relatively small, 0.2 × length of proctiger, and composed of a double row of cells; subgenital plate gradually narrowing to a pointed apex; inner ovipositor valve dorsally broadly triangular in profile ( Figure 4L).
Adult measurements (mm) and ratios (

Immature structure
Body outline elongate, with protruding wing buds lacking humeral lobes ( Figure 7A, D). Antennae of 5th instar ( Figure 7B) with 8 or 9 segments bearing four rhinaria, one each apically on segments 6-9; 3rd instar antennae 5-to 6-segmented bearing three rhinaria, one each on terminal 3 segments. Tarsi with well-developed claws, arolia very small ( Figure 7B). Anus situated terminally, circumanal pore area with large and irregular lateral fields of multiple pores extending to both ventral and dorsal surfaces; circumanal ring medially narrow with a single row of elongate cells ( Figure 7C).

Immature chaetotaxy
Immatures with sparse coverage of short simple setae on body dorsal surface and margins. Dorsal surface of caudal plate/abdominal tergites with small groups of pointed lanceolate setae close to the body margin ( Figure 7A, D).

Biology
The gall is a leaf fold on the margin of the leaf and consists of the lower abaxial surface folding up over the upper adaxial surface to make the gall on the upper leaf surface ( Figure 3B).

Etymology
A noun in the genitive case, named in reference to the host plant genus Allophylus.

Comments
This species is placed in the hitherto monotypic genus, Cornegenapsylla Yang and Li, 1982. It shares with the type species, C. sinica, the forewing pattern with bands of dark pigmentation around the veins, the forewing shape (the forewing being elongate with an almost rectangular apex), and the head shape, though it lacks the well-developed genal processes of C. sinica (comparison of forewing, head and male terminalia are provided in Figure 5A-F). It differs most distinctly from C. sinica in the larger body size, the very short genal processes, the swollen 3rd antennal segment, the male subgenital plate produced into a posterior bulge, the elongate shape of the female terminalia, the immature morphology, and the host plant species and galling biology. Both species produce galls on host plants in the family Sapindaceae, but C. sinica immatures produce deep pit galls on young leaves of Dimocarpus longan (Yang 1984), whereas C. allophyli immatures produce enclosed galls on the leaf margins of mostly mature leaves of Allophylus cobbe. These different biologies are reflected in the different immature structure and chaetotaxy, with C. sinica immatures showing the ventro-dorsally flattened body form, and marginal placement of setae typical of pit gall formers; whereas C. allophyli immatures have irregularly dispersed simple setae and non-flattened, broadly inflated body form typical of enclosed gall formers.
Ongoing work by I.M. suggests that Cornegenapsylla is affiliated with the Neotropical genus Phacosemoides Lima and Guitton, 1962, as well as a number of species from the Afrotropical Pseudophacopteron caffrariense-group as defined in Malenovský and Burckhardt (2009).

Comments
With the synonymization of Neophacopteron euphoriae and Cornegenapsylla sinica by Li (2011), it is confirmed that there is a single species on longan that is widely distributed in South East Asia. Burckhardt and Ouvrard (2012) mistakenly mention the combination Cornegenapsylla euphoriae (Yang, 1984) when reinstating Cornegenapsylla as a valid genus. Cornegenapsylla sinica remains unusual within the Phacopteronidae for the long genal processes and the male terminalia covered with stout lanceolate setae, as well as a characteristic near vertical feeding posture (Yang et al. 2009). Without an explanation, but probably based on the relatively well-developed genae in the type species of Phacopteron Buckton, 1896, Li (2011) placed C. sinica in Phacopteron, which was subsequently reversed by Burckhardt and Ouvrard (2012 (Hodkinson 1986;Li 2011), which dehisces after adult eclosion inside the gall (Raman 1987). A similar biology with emergence of the adult from a sac-like gall is illustrated here for Pauropsylla udei (Singapore specimens) on Ficus variegata ( Figure 3E). The 1st-5th instar immatures of C. sinica were described and illustrated by Yang (1984). The 5th instar body margin is bordered with bluntly pointed setae situated on cuticular tubercles and the dorsum of 5th instars has sparsely distributed minute clubshaped setae ( Figure 7E). Here we provide illustrations of 2nd, 3rd and 5th instars (Singapore specimens, Figure 7E, F, H), and a 3rd instar immature (Thailand specimens) showing the production of waxy filaments from the large pointed dorsal setae ( Figure 7G). In contrast to C. allophyli sp. nov., the antenna of 5th instar immatures of C. sinica is 6-to 7-segmented, bearing only two rhinaria on the apical segments, and the anus is situated ventrally, surrounded by a small transverse circumanal ring composed of a single row of cells.

Biology
The immatures produce deep pit galls on young leaves (Yang 1984). Cornegenapsylla sinica is a pest of longan, an important fruit crop in South East Asia. It causes economic damage by direct effects of feeding, and possibly as well by the transmission of a ‛filamentous virus' (a suspected phytoplasma, cf. Nguyen et al. 2012) that is the agent of longan witches' broom disease (Chen et al. 1992Xu et al. 2001;Yen et al. 2005).

Comments
Both the host plant and the psyllid are widespread in Asia. We report new records on Alstonia sp. (probably Alstonia scholaris or A. brassii) for mainland PNG, Central and Madang Provinces, while psyllid galls on Alstonia scholaris probably induced by this species have been recorded from Ralum, Bismarck Archipelago by Rübsaamen (1905). The host is used in agroforestry for timber as well as other uses and is also planted as an ornamental (Orwa et al. 2009). Pseudophacopteron tuberculatum is considered a serious pest of plantations of Alstonia scholaris in the Philippines (Braza and Calilung 1981). Its taxonomy, however, is in need of revision because there are likely to be undescribed species on the same host in the Oriental and Australasian Regions (BMNH data) and Pseudophacopteron alstonium Yang and Li, 1983, which is similar to Pseudophacopteron tuberculatum, was described from Alstonia scholaris in China (Li 2011). The specimens cited above from PNG correspond well in their morphology with the original description (Crawford 1912) and type specimens of Pauropsylla tuberculata in USNM examined by I.M.

Biology
This species makes enclosed conical or barrel-shaped galls usually on the leaf blade, and often along the mid-vein. Mathur (1935) noted about 20 scattered galls on a single leaf. More rarely galls can be found on young fruits or branches (Houard 1923;Mani 1948Mani , 1964. The galls have been described and illustrated by several authors (e.g. Rübsaamen 1905; Docters van Leeuwen-Reijnvaan and Docters van Leeuwen-Reijnvaan 1910, 1916Uichanco 1919;Houard 1923;Mani 1964;Yang and Li 1983).

Discussion
Many more psyllid species undoubtedly remain to be discovered and described from PNG and adjacent regions. Determining the taxonomic affinities of the Trioza species described here is partly hindered by the current poor knowledge of the regional fauna and the fluctuating state of revisionary systematics in the family Triozidae. It is unlikely that either of the Trioza species described here will be of economic importance.
In contrast, the fruit of Allophylus cobbe is edible and locally popular, sometimes known commonly as the 'Fijian Longan', and therefore Cornegenapsylla allophyli has the potential to have an economic impact, but, despite the widespread distribution of the host-plant from India, China, Thailand, out to Pacific Islands such as Fiji and Samoa (Orwa et al. 2009), the psyllid may not be sufficiently abundant or widespread to be considered a potential pest. Several other phacopteronid species are known as pests of economically important fruit or timber trees, especially in South East Asia, including the congeneric Cornegenapsylla sinica, which injures shoots and leaves of longan (Dimocarpus longan) and may be a viral or phytoplasma vector. In addition, Pseudophacopteron album (Yang and Tsay 1980) (= P. canarium Yang and Li, 1983) is a serious pest of Chinese olive (Canarium album) in South China, necessitating control measures (Lu and Liu 2001;Li 2011); heavy infestations of Pseudophacopteron calilungae Navasero, 1998 damage the inflorescences of pili nut (Canarium ovatum) in the Philippines (Navasero 1998); and Pseudophacopteron tuberculatum (Crawford 1912) causes economic loss in plantations of white cheese-wood (Alstonia scholaris) in the Philippines (Braza and Calilung 1981).
The intraspecific variation, and seeming interspecific convergence, in gall types produced by P. triozoptera and P. udei from different regions is striking and needs to be investigated further. Gall phenotypes are usually conserved within species (e.g. Lonchocarpus-feeding psyllids from Central America; Hollis and Martin 1997), but the gall variation reported here does not correlate well with adult morphological variation or host variation. Together, genetic divergence and the different gall types suggest that there are grounds to more closely examine morphological divergence. The presence of multiple species would not be surprising over such large geographic distributions, but it remains surprising that there is not more morphological divergence evident. Only more comprehensive sampling from across the Oriental Region for both species is likely to yield a better understanding of these patterns of variation.
České Budějovice) for loans or gifts of material. We are grateful to Daniel Burckhardt, David Ouvrard, and one anonymous reviewer for helpful comments that improved the manuscript.

Disclosure statement
No potential conflict of interest was reported by the authors.