Jumping plant lice of the genus Aphalara (Hemiptera, Psylloidea, Aphalaridae) in the Neotropics

Abstract The Neotropical species of the predominantly north temperate genus Aphalara are reviewed. Four species are recorded here from this region, two of which are described as new. Aphalara ritterisp. nov. occurs in southern Brazil (Paraná, Rio Grande do Sul, Santa Catarina) and represents the first and only species reported from South America. A second new species, Aphalara ortegaesp. nov., is described from Mexico and Puerto Rico. Another two species, Aphalara persicaria Caldwell, 1937 and A. similaCaldwell, 1937, have been previously reported from Mexico and the USA, and one of them also from Cuba. The two new species are both associated with Persicaria hydropiperoides and P. punctata (Polygonaceae) on which the immatures induce leaf roll galls. The two new species are morphologically similar to A. persicaria, to which they are probably closely related. A key is provided for the adults and immatures of the Neotropical species of Aphalara.


Introduction
Jumping plant lice or psyllids (Hemiptera, Psylloidea) are generally very host specific sternorrhynchous insects developing on eudicots, Magnoliales and, exceptionally, also on monocots and conifers. The largest diversity is encountered in the tropics and south tem-

Materials and methods
The material of the new species was collected by D. Burckhardt   The morphological terminology follows mostly Brown and Hodkinson (1988), Ossiannilsson (1992), Burckhardt and Lauterer (1997) and Hollis (2004). The terminology of the structures on the head is detailed in Fig. 4. Plant names correspond with WFO (2020).  Morelia;19.7029, -101.1964;1920 m a.s.l.;Jun. 1965 Diagnosis. Adults. General body colour dark brown in males, medium brown in females. Forewing with brown clavus. Head with small anteorbital tubercles; anterior tubercles small, rounded; outer anterior margin weakly concave. Clypeus long, tubular, visible in dorsal view. Forewing 2.6-2.9× as long as wide; surface spinules moderately thick, in males leaving narrow or no spinule-free stripes along the veins, arranged in squares or rhombi or indistinct transverse rows, in females covering the whole mem- brane up to veins, arranged in irregular transverse rows. Paramere, in profile, lamellar with large, claw-like antero-subapical inner process, which is relatively deeply incised, postero-apical edge large, inner face with a few scattered setae. Distal portion of aedeagus with straight shaft and semi-circular apical inflation. Female proctiger strongly incised in the middle forming a slightly curved apical process; circumanal ring expanded into a large, apron-shaped, slightly angular area distally. Subgenital plate with apex almost straight, in ventral view. Valvula dorsalis only weakly curved dorsally. Fifth instar immatures. Body 1.5-1.6× as long as wide. Antenna 0.5× as long as forewing pad. Outer circumanal ring angular laterally, relatively strongly convex postero-laterally. (Fig. 3A-D). Colour. General body colour dark brown in males, medium brown in females. Vertex dark straw-coloured with slightly oblique dark band on either half of vertex. Clypeus dirty yellowish. Antennal segments 1 and 2 light brown, 3-8 yellow becoming darker towards the apical segments, 8 and 9 dark brown. Pronotum with three large yellow areas on either half. Mesopraescutum with yellow posterior third; mesoscutum with three longitudinal yellow stripes on either side. Femora light brown, tibiae and tarsi yellow. Forewing transparent, membrane often yellow or with light brown stripes along the veins; clavus brown. Younger specimens lighter.
Fifth instar immatures (Fig. 8D, G). Colour. General body colour light greyish brown, membranes yellow, dorsally slightly darker than ventrally. Structure. Body 1.5-1.6× as long as wide. Head, antennae and legs with slender lanceolate setae. Antenna 0.5× as long as forewing pad. Tarsal arolium slightly longer than claws, rounded, without unguitractor and pedicel. Forewing pads large with marginal lanceolate setae of irregular length; humeral lobe well developed. Caudal plate irregularly rounded posteriorly, dorsally with sparse microscopic setae, margin with lanceolate setae. Outer circumanal ring angular laterally, relatively strongly convex postero-laterally, consisting of two unequal rows of pores (Fig. 8G).
Eggs. Colour unknown. Oblong oval; with short apical filament. Etymology. Named after Professor Dr Laura Maria Ortega, Texcoco, Mexico, in recognition for her support and help during our field work in Mexico. A noun in the genitive case.
Host plants, biology and habitats. Persicaria hydropiperoides (Michx.) Small, P. punctata (Elliott) Small (Polygonaceae). Immatures induce leaf roll galls in which they develop. In Mexico, we collected the species in damp areas around a pond or near a river.
Affinities. Aphalara ortegae sp. nov. belongs to the A. calthae (Linnaeus, 1761) group, as defined by Burckhardt and Lauterer (1997), which is characterised by the apical inflation of the distal portion of the aedeagus which lacks a dorso-apical mem-branous sack. It is morphologically similar, and probably closely related, to A. curta Caldwell, 1937, A. persicaria and A. ritteri sp. nov. in the caudally strongly expanded circumanal ring on the female proctiger and the absence of a brown transverse band on the forewing. Aphalara ortegae differs from these species in the surface spinules on the forewing which are denser, forming often transverse rows, and the caudal pore field on the female proctiger which is slightly narrowed distad to circumanal ring, large and relatively angular. The paramere of A. ortegae has a slightly smaller antero-apical claw than that of A. curta, and a larger postero-apical lobe than that of A. persicaria and A. ritteri. The immatures of A. ortegae and A. ritteri are almost identical but differ from those of A. persicaria in the angular outer circumanal ring (immatures of A. curta are unknown). See also identification keys. Caldwell, 1937 Figures 5K, L, 6I, J, 7C, D, J, 8E, H Aphalara persicaria Caldwell, 1937: 565;Caldwell (1938a) (1); NMB-PSYLL0004616; NHMB, dry mounted. Diagnosis. Adults. General body colour orange to light brown. Forewing with brown apical part of clavus. Head with small anteorbital tubercles; anterior tubercles small, rounded; outer anterior margin strongly concave. Clypeus long, tubular, visible in dorsal view. Forewing 2.5-2.7× as long as wide; surface spinules fine, forming irregular squares or rhombi; in males often leaving narrow spinule-free stripes along veins (Fig. 5K), in females usually covering the entire wing membrane up to veins (Fig. 5L). Paramere, in lateral view, lamellar, straight, only weakly narrowed in the middle; dorsal margin sclerotised, straight or weakly curved; thumb-like process near antero-apical edge, short, narrow and weakly curved (Fig. 6I). Distal portion of aedeagus with straight shaft and inflated apical third that bears an antero-apical hook of variable length (Fig. 6J). Female proctiger, in lateral view, incised distal to circumanal ring (Fig. 7C), which is strongly expanded caudally (Fig. 7J). Dorsal margin of valvula dorsalis almost straight (Fig. 7D). Fifth instar immatures. Body (Fig. 8E) 1.6-1.7× as long as wide. Forewing pads narrow, humeral lobes broadly rounded; small lanceolate setae present along margin but not on dorsum. Caudal plate narrowly rounded; lanceolate setae present along margin, approximately as long as distance between them. Outer circumanal ring rounded laterally (Fig. 8H). The single female from Mexico was collected on P. hydropiperoides (Michx.) Small, which is a probable host. We collected specimens in Mexico and the USA (Florida, Michigan, Virginia) in wet meadows near ponds or rivers.  Diagnosis. Adults. General body colour dark brown to almost black in males, brown to dark brown in females. Forewing with clavus dark brown or almost black, contrasting from surroundings. Head with small anteorbital tubercles; anterior tubercles small, rounded; outer anterior margin weakly concave. Clypeus long, tubular, visible in dorsal view. Forewing 2.6-2.9× as long as wide; surface spinules relatively fine, in males leaving narrow or wide spinule-free stripes along the veins, arranged in squares or rhombi, in females leaving narrow or no spinule-free stripes along the veins, arranged in squares or rhombi. Paramere, in profile, lamellar with medium-sized, claw-like antero-subapical inner process, which is shallowly incised, postero-apical edge mediumsized. Distal portion of aedeagus with curved shaft. Female proctiger strongly incised in the middle forming a hardly curved apical process; circumanal ring expanded into a large, apron-shaped, transverse, laterally rounded area distally. Subgenital plate with apex slightly indented, in ventral view. Valvula dorsalis distinctly curved dorsally. Fifth instar immatures. Body 1.5-1.6× as long as wide. Antenna 0.4× as long as forewing pad. Outer circumanal ring angular laterally, relatively weakly convex postero-laterally.

Aphalara ritteri
Description. Adults (Figs 1A-C; 3E-H). Colour. General body colour dark brown to almost black in males, brown to dark brown in females. Vertex ochreous with slightly oblique dark band on either half of vertex. Clypeus dirty yellowish. Antennal segments 1 and 2 brown, 3-8 yellow, strongly contrasting from dark brown segments 9 and 10. Pronotum with three ochreous dots on either half. Mesopraescutum with yellow posterior margin and a narrow lighter longitudinal stripe in posterior half; mesoscutum with three narrow longitudinal yellow stripes on either side. Femora brown, tibiae and tarsi yellow. Forewing transparent, membrane often yellow or fumate, veins light to dark brown; stripe along vein Cu 1b and clavus dark brown or almost black, contrasting from surroundings. Young specimens lighter, sometimes orange or light brown.
Fifth instars immature (Figs 1D, 8F). Colour. General body colour, when alive, with yellowish to brown sclerites and yellow membranes; in ethanol straw-coloured to light brown, membranes yellow, dorsally slightly darker than ventrally.
Etymology. Named after Markus Ritter, Basel, Switzerland, in recognition of his support of the project on Brazilian psyllids as a president of the Pro Entomologia. A noun in the genitive case. Distribution. Brazil (Paraná, Rio Grande do Sul, Santa Catarina). Host plants, biology and habitats. Persicaria hydropiperoides (Michx.) Small, P. maculosa Gray, P. punctata (Elliott) Small (Polygonaceae). The immatures induce leaf roll galls in which they live, usually one immature per gall. The galls are uniformly green or rarely reddish ( Fig. 2A-C). Sometimes aphids (Fig. 1E), soft scales and thrips are found in the galls which may be there accidentally or for the nutritionally favourable conditions the galls offer. Eggs are laid on the margin of the leaf rolls. Adults, often together with immatures, were collected from December to February and April to July. It is currently not possible to decide whether this reflects the presence of well-defined generations or an artefact of insufficient collection. Recorded in humid areas in parks, riverine vegetation and Atlantic forest.
Affinities. See under Aphalara ortegae sp. nov. Diagnosis. Adults. General body colour orange to light brown. Forewing with light or brown clavus. Head with small anteorbital tubercles; anterior tubercles small, rounded; outer anterior margin strongly concave. Clypeus long, tubular, visible in dorsal view. Forewing 2.4× as long as wide; surface spinules moderately thick, forming irregular squares or rhombi; in males often leaving narrow spinule-free stripes along veins, in females usually covering the entire wing membrane up to vein). Paramere, in lateral view, lamellar, straight, weakly widening to apex; dorsal margin sclerotised, straight, postero-apical edge angular; apex of thumb-like process level with antero-apical edge, long, broad (Fig. 6K). Distal portion of aedeagus with straight shaft and relatively evenly widening apical inflation (Fig. 6L). Female proctiger, in lateral view, not incised distal to circumanal ring (Fig. 7G), which is not expanded caudally (Fig. 7L). Dorsal margin of valvula dorsalis almost straight (Fig. 7H).

Aphalara spp.
Comments. Burckhardt (1987) reported a single female from Argentina (Tucuman) suggesting that it may be introduced from North America. Whether this specimen belongs to A. ritteri sp. nov. cannot be checked as it appears to be lost (T. Vasarhelyi, pers. comm.). Brown and Hodkinson (1988) recorded a female in poor condition from Panama (Canal Zone, Herbert Osborn Collection) (USNM, slide mounted) that they questionably referred to A. curta. As the specimen is in poor condition, its identity cannot be determined. Paramere with distinctly expanded lobe postero-apically (Fig. 6A, B, E, F, arrow). Distal portion of aedeagus with abruptly widening apical dilatation ( Fig. 6 C Paramere with relatively large antero-apical thumb-like process (Fig. 6A, B). Distal portion of aedeagus straight basally (Fig. 6C, D) Paramere with relatively small antero-apical thumb-like process (Fig. 6E, F). Distal portion of aedeagus curved basally (Fig. 6G, H) Circumanal ring consisting mostly of two unequal rows of pores, hardly expanded caudally (Fig. 7L)  Surface spinules moderately thick, arranged in irregular transverse rows (Fig. 5D, J)  Surface spinules fine, arranged in irregular squares or rhombi (Fig. 5H, L, N)...7 7

Discussion and conclusions
Aphalara is an atypical psyllid genus with respect to distribution and host plant range as it is predominantly north temperate and associated with herbaceous plants, mostly Polygonaceae. Ouvrard (2020) lists 46 Aphalara species, five of which of unresolved taxonomic status or considered nomina dubia (Aphalara crassinervis Rudow, 1875;A. hedini Enderlein, 1933;A. multipunctata Kuwayama, 1908;A. poligoni (Shinji, 1938); and A. tecta Maskell, 1898). Among the remaining species (plus the two new added here), 15 occur in the New World and 28 in the Old World. Three Asian species (11% of the Old World species) are known only from outside the Palaearctic realm (Aphalara ossiannilssoni, A. siamensis and A. taiwanensis), the first two from a single locality in India (West Bengal) and northern Thailand, respectively, and the last from several localities in Taiwan (Mathur 1975;Burckhardt and Lauterer 1997). Aphalara fasciata occurs in both the Palaearctic and Oriental regions (Burckhardt and Lauterer 1997). Hence, 14% of the Old World species are found outside the Palaearctic region. A similar pattern is found in the New World where four of the 15 known species (27%) are found south of the Mexico-USA border though the number of species existing in the Nearctic is probably much higher. Aphalara ortegae sp. nov. is widely distributed and likely native in Mexico and Puerto Rico. Aphalara ritteri sp. nov. is widely distributed in Southern Brazil (PR, RS, SC) in suitable habitats and most probably native as it is associated with native hosts.
Of the 15 New World species, five are associated with Rumex, three with Persicaria, and one with Polygonum spp. (all Polygonaceae) as well as each one on the unrelated Lysimachia ciliata (Primulaceae) and Sisymbrium canescens (Brassicaceae); hosts of four species are unknown. In the Old World, seven species are associated with Rumex, four each with Persicaria and Polygonum, one with Persicaria and Polygonum and two with Reynoutria spp. (all Polygonaceae) as well as two species with the unrelated Caltha (Ranunculaceae) and one with Stellaria (Caryophyllaceae), in addition to six species with unknown hosts. Among the Polygonaceae feeders, 18 Aphalara species appear monophagous, seven oligophagous on plant species of the same genus and one oligophagous on several plant species of two genera (Burckhardt and Lauterer 1997; Ouvrard 2020). The three closely related, A. ortegae, A. persicaria and A. ritteri, are oligophagous on Persicaria spp. sharing some host species, such as P. hydropiperoides and P. punctata.
The two odd specimens recorded from Argentina (Burckhardt 1987) and Panama (Brown and Hodkinson 1988) seem, in the light of the new records from Brazil and Mexico, less out of place and may represent the two species newly described here.
Aphalara ortegae sp. nov. and A. ritteri sp. nov. are morphologically similar to each other and to A. persicaria with many characters intergrading between species, emphasising the importance of sufficiently large series of material with adults and immatures together with host information for taxonomic work in this genus.