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Uroleucon nahuelhuapense Nieto Nafría & von Dohlen, 2019 Studied new material. ARGENTINA, Neuquén province, Los Lagos department, Santa María: km. 32 road 231 (40º 55’ S 71º 26’ W, 800 m a.s.l.) —species type locality—, on Adesmia boronioides, 10-January-2019, Ortego leg., 12 apterous viviparous females, 9 alate viviparous females, 19 oviparous females and 14 males, collections of the University of León (León, Spain) and The Natural History Museum (London, United Kingdom). Apterous viviparous females. Figures 1 A–1C. Mounted specimens of the new material show varying pigmentation patterns; some are similar to those of the type-specimens, while others show more extensive or intense head, antennae, legs and siphunculi pigmentation (Figure 1). In quantitative characters the new specimens are similar to those of type-specimens, although they extend the ranges of several features (Table 2); it does not appear that greater or lesser measurements or quantities are correlated with greater or lesser pigmentation. Alate viviparous females. Figure 2. Colour when alive bright emerald green, similar to apterous viviparae, with more-or-less dark brown head, antennae, most of legs and siphunculi. Body 2.88–3.88 mm long and pearshaped with long legs and antennae. In mounted specimens, abdomen pale in general with strong contrast to head and thorax, including antennae, rostrum and legs; these and the siphunculi are strongly pigmented, similar to those of the well-pigmented apterous viviparae. Alatae are also similar to apterae in many other qualitative characters (see Nieto Nafría et al. (2019) for apterous females) differing from them by having large and pigmented marginal sclerites on abdominal segments 1 to 4 that bear several setae, and small abdominal intersegmental muscular sclerites that are paler than the neighbouring segmental sclerites. Metric and meristic features in Table 2. Oviparous females. Figures 3A and 3C. Similar overall in both alive and mounted specimens to apterous viviparous females, and also in body length and pigmentation variation. Differing in having a more pigmented subgenital plate with more setae, and a slightly swollen proximal part of the hind tibiae bearing most of the scent plates, which are diverse in size and form. Metric and meristic data are in Table 2. Males. Figure 3B. Apterous. Brown-greenish when alive. They are also very similar to females, although slightly smaller, with shorter siphunculi and cauda; the cauda is more or less triangular. When mounted, pigmentation is also varied, although coxae, trochanters and cauda are darker than in females. In addition, setiferous sclerites on thoracic and abdominal segments are conspicuously larger and darker, marginal sclerites tend to coalesce between them, and there are dispersed ventral sclerites on abdominal segments 2 to 6 and a transverse band on segment 7. Quantitative features are in Table 2. ......continued on the next page Bionomics and geographical distribution. The new specimens do not change what is already known of the species with regard to its host plant, Adesmia boronioides, or geographical distribution, which is restricted to the eastern bank of Nahuel Huapi lake in the Argentinian province of Neuquén (Nieto Nafría et al. 2019). Discussion. The observed differences in pigmentation between specimens of all morphs can be explained as intraspecific variability independent of geography or host plant. The variation affects specimens from the same location and on the same plants, which were collected at the same or similar time of year (the new specimens were collected in mid-January and the type specimens were collected in mid-December). The great similarities that the specimens of this species —viviparous and oviparous females and males— present generally, in many qualitative details and most quantitative features, are highly remarkable. The apterism of the males and the small swelling of hind tibiae in oviparous females can be related to a monoecious, non-host-alternating, life cycle. The brevity of the life cycle of the species is also very remarkable; sexuales are present in the first summer month in a locality of very moderate altitude, which undoubtedly hinders collection of this species in other locations and impedes the knowledge of its distribution., Published as part of Durante, M. Pilar Mier, Ortego, Jaime, Von Dohlen, Carol D. & Nafría, Juan Manuel Nieto, 2020, A further contribution to the knowledge of Uroleucon species (Hemiptera, Aphididae) living on Adesmia (Fabaceae) in southern South America, with description of a new species from Chile, pp. 548-560 in Zootaxa 4748 (3) on pages 550-553, DOI: 10.11646/zootaxa.4748.3.8, http://zenodo.org/record/3701139, {"references":["Nieto Nafria, J. M., von Dohlen, C. D., Moreno-Gonzalez, V., Ortego, J. & Mier Durante, M. P. (2019) The species of Uroleucon (Hemiptera: Aphididae) living on Adesmia (Fabaceae) in Argentina, with description of a new species. Zootaxa, 4555 (4), 561 - 572. https: // doi. org / 10.11646 / zootaxa. 4555.4.7"]}

Uroleucon nahuelhuapense Nieto Nafría & von Dohlen, sp. n. Types. Holotype: apterous viviparous female, ARGENTINA, Neuquén province, Villa La Angostura: Santa María (road 231, km. 32), 40° 55 'S 71° 26’ W, 800 m; on Adesmia boronioides; December 14, 2009; Mier Durante, Ortego and Nieto Nafría leg., sample ARG 1670, specimen number 1; collection of the University of León (León, Spain). Paratypes: 32 viviparous apterous females of the same sample, collected at the same time as the holotype; collections of the University of León (León, Spain), Jaime Ortego (Mendoza, Argentina) and The Natural History Museum (London, United Kingdom). Apterous viviparous females. Figure 1. Based on 33 specimens. Colour when alive bright emerald green with brownish-green siphunculi. Body 2.90-3.53 mm long and pear-shaped with long legs and antennae. Mounted specimens more-or-less light brown with darkened head, rostrum, anal plate, cauda and usually antennae and legs, and brown to dark-brown siphunculi. Setae on dorsum of body, antennae and legs (except those on tarsi and end of tibiae) thick and with apex indistinct or truncate; other setae more-or-less pointed. Marginal tubercles absent. Several specimens have one or two very minute cephalic spinal tubercles. Frons sinuous, medial-frontal tubercle lower than the frontal-lateral (or antennal) tubercles. Cephalic setae with the more usual pattern in the South American species of the genus: behind the four aligned frontal setae there are from front to back one pair (anterior discal), one pair (posterior discal) and a transverse postero-cephalic line with four setae. Antennal segments I and II similar in colour to head or in part darker than it, especially around the ventro-medial muscular impressions of segment I and near the end of segment II; antennal segment III smooth as in the proximal ones, with a short proximal part pale brown as in the proximal segments and progressively darkened to a dark brown or near-black apical ring; remainder of antenna progressively darkened and imbricated. Sensoria round and with thick walls; primary sensoria ciliate; secondary sensoria small, non-protruding and aligned, with the most proximal one at the end of the paler part of the segment. Rostrum surpassing middle coxae and darkening to apex. Ultimate rostral segment relatively narrow. Coxae and trochanters more-or-less pigmented than head and most of femora, which present a more-or-less extensive dorso-apical area darker than the remaining segments. Tibiae somewhat darker than the femora and with 1/7-1/8 of their length apical dark brown or almost black. Tarsi short and as dark as the distal end of tibiae and second segment with ventral setae. Setiferous sclerites on thorax and on pre-siphuncular abdominal segments small or very small, mostly unpigmented, near inconspicuous. Pre- and post-siphuncular sclerites absent. Intersegmental muscular sclerites absent. Spiracular sclerites small and light brown. Siphunculi progressively pigmented, brown to dark brown, cylindrical with enlarged proximal part, in most of the length a little wider than hind tibiae; transverse striae in the paler anterior half, scales progressively more marked on the distal portion prior to reticulation, which is ill defined; flange little marked. Setiferous sclerites on abdominal segments 6 to 8 and more-or-less light pigmented; those on VIII segment can be partially fused, without forming a continuous transverse sclerite. Subgenital plate pale, not darker than the ventral part of anterior abdominal segment and paler than anal plate and cauda, which are scarcely pigmented. Cauda lanceolate, with a marked proximal narrowing and more-or-less blunt at the apex; its setae are all similar in length and longer than the caudal width at the middle. Metric and meristic features in Table 2. Alate viviparous females and sexuales. Unknown. Etymology. The specific name nahuelhuapense is a supposed demonym of Nahuel Huapi lake, in neutral gender because Uroleucon is neutral. Bionomics. Aphids feed on the small stems of Adesmia boronioides Hook. f. (Fabaceae), which is its only known host plant. Sexuales are unknown, but the species is likely to be holocyclic, because of cold temperatures during winter. Geographical distribution. The new species is currently known in one locality of the Andean slopes of the Argentinean province of Neuquén, very close to the shore of the Nahuel Huapi lake. It is possible that the species occurs on the same plant species or on other species of Adesmia in other localities of similar altitude in Argentina or even in Chile. Molecular analyses. Amplification and sequencing of the tRNAleu-COII locus were performed successfully and resulted in divergent sequences for all South American taxa. Sequences obtained were deposited in GenBank (Table 1). Taxonomic discussion. M.P. Mier and J. Ortego had some difficulty in 2008 convincing reviewers of the manuscript describing U. adesmiae that the new species should be classified as Uroleucon, because its host plant was in Fabaceae, not Asteraceae or Campanulaceae, the usual host-plant families of Uroleucon (Mier Durante & Ortego, 2008). Furthermore, several morphological features of U. adesmiae were not typical of Uroleucon (almost total absence of setiferous sclerites as well as pre- and post-siphuncular sclerites). Justification of U. nahuelhuapense sp. n. as a Uroleucon is simpler because there is a great resemblance to U. adesmiae and U. payuniense Ortego & Nieto Nafría 2007 (see Mier Durante & Ortego, 2008), and because it shares the genus of host plant with U. adesmiae. This classification is further justified by genetic evidence. The tRNAleu-COII mitochondrial sequences confirm the correct placement of U. nahuelhuapense sp. n. (as well as U. adesmiae) within Uroleucon (Figure 2). Both species living on Adesmia form a cluster with other South American native Uroleucon and one Euro-Asiatic species, U. rapunculoidis (Börner, 1939). While U. nahuelhuapense sp. n. and U. adesmiae are clustered most closely to each other, the magnitudes of their pairwise patristic distance (sum of branch lengths on the dendrogram) and Tamura-Nei distance are as great or greater than the distances between other established, valid species in the comparison (Table 3). Thus, these two taxa exhibit species-level genetic distances from each other and from other described Uroleucon, both South American and Northern Hemisphere species. It is generally accepted that the subgeneric classification of Uroleucon requires a thorough revision (see Blackman & Eastop, 2018). Our phylogenetic studies of Uroleucon in progress suggest that the South American species are not a monophyletic group, and that the subgenera as currently understood are not monophyletic (see also Moran et al., 1999). Until the necessary revision can be undertaken, however, it seems appropriate to place Uroleucon nahuelhuapense sp. n. in the subgenus Lambersius Olive, 1965, according to the concept of that subgenus in Nieto Nafría et al. (2007). Uroleucon nahuelhuapense sp. n. and U. adesmiae, the two species of Uroleucon living on Adesmia species, can be morphologically distinguished from one another by antennal pigmentation (darker in U. nahuelhuapense sp. n. than in U. adesmiae) and by different numbers of setae on the cephalic dorsum, on the ultimate rostral segment, on both dorsum and venter of abdominal presiphuncular segments, on genital plate and on cauda (see Table 2). Thirty species of Uroleucon have been recorded from South America: U. adesmiae Mier Durante & Ortego, 2008, U. aeneum (Hille Ris Lambers, 1939), U. ambrosiae (Thomas, 1878), U. bereticum (Blanchard, 1922), U. brevisiphon de Carvalho, 1998, U. chilense (Essig, 1953), U. compositae (Theobald, 1915), U. erigeronense (Thomas, 1878), U. essigi de Carvalho, 1998, U. eumadiae Delfino & Gonzales, 2005, U. garnicai Delfino, 1991, U. gochnatiae Delfino, 1994, U. gravicorne (Patch, 1919), U. jaceae (Linnaeus, 1758), U. littorale (Blanchard, 1939), U. macolai (Blanchard, 1932), U. malarguense Ortego & Nieto Nafría, 2007, U. mendocinum Mier Durante & Ortego, 2007, U. muermosum (Essig, 1953), U. nahuelhuapense sp.n., U. nuble (Essig, 1953), U. patagonicum Nieto Nafría & Seco Fernández, 2007, U. payuniense Ortego & Nieto Nafría, 2007, U. petrohuense de Carvalho, 1998, U. pseudomuermosum de Carvalho, 1998, U. riojanum Nieto Nafría & Mier Durante, 2007, U. rudbeckiae (Fitch, 1851), U. sonchi (Linnaeus, 1767), U. tessariae Delfino, 1994 and U. tucumani (Essig, 1953). Four of them: U. aeneum, U. compositae, U. jaceae and U. sonchi are species wide-distributed and not native to the Americas, they can be easily separated to the others 26 species, which are South American or North American native species, because they have coxae wholly dark brown to black, as pigmented or nearly as pigmented as distal apices of femora, tibiae and most part of siphunculi, which are dark-brown to black sometimes with paler middle portion. In other 26 species coxae are yellowish brown to brown, less pigmented than distal part of siphunculi and usually less pigmented than the distal area of femora, and siphunculi are variably pigmented but if the middle part is not as dark as proximal and distal part then cauda is triangular shaped, not lanceolate. Most part of these 26 species are restricted to South America, only U. ambrosiae (Thomas, 1878), U. erigeronense (Thomas, 1878), U. gravicorne (Patch, 1919) and U. rudbeckiae (Fitch, 1851) are also known in North America. parentheses are exceptional data, or very exceptional if parentheses are duplicates. Bold characters in the Uroleucon adesmiae column indicate that the previously known corresponding limit has been modified with the new data. Arrows, single or double, indicate the most important characteristics to differentiate both South American species of Uroleucon living on Adesmia. ......continued on the next page The following key permits the separation of the Uroleucon species with relatively pale coxae, as it has been detailed before, recorded from South America. It is based on that by Nieto Nafría et al. (2007), which in turn was based on the key by de Carvalho et al. (1998); several disjunctive couplets have been simplified. Uroleucon littorale was described from a locality in the Argentine province of Entre Ríos, it has not yet been collected and its original description is not too eloquent; it is very similar to U. tucumani, of which it can be synonymous in opinion by Blackman & Eastop (2018); it is not included in the key. The measurements are lengths unless otherwise indicated. In brackets are morphological data which do not have correspondence in the other proposition of the disjunctive, but which are useful to secure identification. Information on the distribution of each species has been actualized from our bibliographic registers. It includes countries for South America, regions for Chile and provinces for Argentina. Records from the Federal Capital of Argentina, Ciudad Autónoma de Buenos Aires, are joined to records from the Buenos Aires province. The names of Chilean regions Aysén del General Carlos Ibáñez del Campo, Libertador General Bernardo O’Higgins and Metropolitana de Santiago are simplified respectively to Aysén, O’Higgins and Santiago. 1 Ventral hairs on proximal 2/3 of hind tarsi second segment small or atrophied. [Siphunculus 1.0–1.2 times cauda. Marginal tubercles present on abdominal segment 2 to 5. Alatae with protuberant secondary sensoria on antennal segment III. Green in life]. On composite species, mainly of genera Erigeron and Solidago. Probably Neartic in origin; Brazil, Colombia, Venezuela......................................................................................... U. gravicorne - Ventral hairs on proximal 2/3 of hind tarsi second segment similar in shape and length to others ventral hairs on this segment and on other tarsi.................................................................................... 2 2 Antennal segment VI processus terminalis longer than 1.2 mm. Siphunculi at least 2.3 times cauda, thin, brown with a pale proximal portion, and reticulated at most on 15% of total length. [Probably pale green with brown o brownish head and partially appendages and siphunculi when alive.] On Senecio smithii, Symphyotrichum squamatus and perhaps other composite. Chile: Aysén, Ñuble.............................................................................. U. nuble - Antennal segment VI processus terminalis shorter than 1.00 mm. Siphunculi shorter or longer than 2.3 times cauda, but if longer it has a different appearance or pigmentation or reticulation of those mentioned above........................ 3 3 Posterior part of cephalic dorsum (behind the discal two setae of vertex) with 6–11 setae............................. 4 - Posterior part of cephalic dorsum (behind the discal two setae of vertex) usually with 4 setae (the general feature in the genus)................................................................................................... 6 4 Cauda triangular or long-pentagonal and 0.22‾ 0.30 mm. Abdominal segment 2 to 6 with 1‾2 marginal setae each side [and 5‾13 spinal and pleural setae]. Red with siphunculi dark brown when alive. [Siphunculi brown to dark brown in general often with a less pigmented middle portion]. On Mutisia spinosa. Argentina: Chubut and Neuquén............. U. patagonicum - Cauda lanceolate and 0.27–0.40 mm. Abdominal segments 2 to 4 with 3 or more marginal setae each side. Green or brownish green in life......................................................................................... 5 5 Siphunculi yellowish or very light-brown with paler proximal 1/4. Abdominal segments 2 to 6 with 6‾12 marginal setae each side and 16–27 setae on spinal and pleural areas. Antennal segment VI processus terminalis at least 1.0 times antennal segment III. Siphuncular width at the base 2.4–4.3 times its width at the beginning of the reticulation, which is well sculptured and extends over 12.2–18.9% of its length. Ultimate rostral segment with 7–10 accessory setae. Cauda with 6–9 setae. Dorsoabdominal setae 50–60 µm. Green in life. On Grindelia chiloensis. Argentina: Mendoza................... U. payuniense - Siphunculi homogeneous brown. Abdominal segments 2 to 6 with 3–6 marginal setae each side and 7–20 setae on spinal and pleural areas. Antennal segment VI processus terminalis at most 1.1 times antennal segment III. Siphuncular width at the base 1.6–2.9 times its width at the beginning of the reticulation, which is poorly sculptured and extends over only 8.0–13.4% its length, exceptionally to 14.3%. Ultimate rostral segment with 10–15 accessory setae. Cauda with 10–15 setae. Dorsoabdominal setae 35–45 µm. Dark green to brownish green in life. On Adesmia. Argentina: Chubut and Neuquén...... U. adesmiae 6 Dorso-cephalic setae 18‾36 µm. [Greenish yellow to yellowish pale green in life. Siphunculi with paler proximal portion, more evident in alatae than apterae. Antennal segment III with 4‾25 secondary sensoria on proximal 1/ 2 in apterae and 20‾41 secondary sensoria in alatae]. On species of several composite genera, in South America Baccharis, Conyza, Erigeron, Gutierrezia, Haplopappus and Hysterionica. Nearctic introduced species; Brazil, Colombia, Peru, Venezuela; Argentina: Buenos Aires, Córdoba, Entre Ríos, Jujuy, Mendoza, Salta, San Luis, Santa Fe, Santiago del Estero; Chile: Maule, Santiago, Valparaíso...................................................................................... U. erigeronense - Distal setae on cauda variable in length, if shorter than other caudal setae then usually pointed. Dorso-cephalic setae 30‾75 µm.................................................................................................... 7 7 Ultimate rostral segment 0.21‾ 0.27 mm and 1.5‾1.8 times hind tarsi second segment.............................. 8 - Ultimate rostral segment 0.12‾ 0.22 mm and 0.8‾1.4 times hind tarsi second segment.............................. 9 8 Ultimate rostral segment 0.23‾ 0.27 mm, with 6‾10 accessory setae. Dark reddish to brown or black when alive. On Acrisione denticulata and perhaps on species of Senecio. Brazil; Chile: La Araucanía, Los Lagos................... U. muermosum - Ultimate rostral segment 0.21‾ 0.23 mm, with 18–24 accessory setae. Shiny green in life. On Madia chilensis and M. sativa. Chile: Santiago.............................................................................. U. eumadiae 9 Marginal tubercles protuberant, frequently on abdominal segment 5 and sometimes on abdominal segments 2 to 4. Ultimate rostral segment with 4‾5 accessory setae. [Apterae with 14‾26 secondary sensoria distributed on nearly whole length of antennal segment III.] Probably pale green in life. On unknown composite. Chile: Los Lagos.................. U. petrohuense - Marginal papillae absent on abdominal segment 5, if present on abdominal segments 2 to 4 then not protuberant. Ultimate rostral segment usually with 5 or more accessory setae......................................................... 10 10 Antennal segment VI processus terminalis at most 3.8 times antennal segment VI base. Siphunculi reticulated on at least 35% of their length and yellowish brown to light brown, like cauda, which is lanceolate. Dark-green with dark-brown head. On Baccharis, Gochnatia glutinosa, Gutierrezia, Hyaloceris cinerea and Senecio subulatus. Bolivia; Argentina: Catamarca, Jujuy, La Rioja, Mendoza, Salta, Tucumán............................................................... U. gochnatiae - Antennal segment VI processus terminalis usually at least 3.8 times antennal segment VI base; if 3.1‾3.9 times then siphunculi or cauda h

Uroleucon nahuelhuapense Nieto Nafr��a & von Dohlen, sp. n. Types. Holotype: apterous viviparous female, ARGENTINA, Neuqu��n province, Villa La Angostura: Santa Mar��a (road 231, km. 32), 40�� 55 'S 71�� 26��� W, 800 m; on Adesmia boronioides; December 14, 2009; Mier Durante, Ortego and Nieto Nafr��a leg., sample ARG 1670, specimen number 1; collection of the University of Le��n (Le��n, Spain). Paratypes: 32 viviparous apterous females of the same sample, collected at the same time as the holotype; collections of the University of Le��n (Le��n, Spain), Jaime Ortego (Mendoza, Argentina) and The Natural History Museum (London, United Kingdom). Apterous viviparous females. Figure 1. Based on 33 specimens. Colour when alive bright emerald green with brownish-green siphunculi. Body 2.90-3.53 mm long and pear-shaped with long legs and antennae. Mounted specimens more-or-less light brown with darkened head, rostrum, anal plate, cauda and usually antennae and legs, and brown to dark-brown siphunculi. Setae on dorsum of body, antennae and legs (except those on tarsi and end of tibiae) thick and with apex indistinct or truncate; other setae more-or-less pointed. Marginal tubercles absent. Several specimens have one or two very minute cephalic spinal tubercles. Frons sinuous, medial-frontal tubercle lower than the frontal-lateral (or antennal) tubercles. Cephalic setae with the more usual pattern in the South American species of the genus: behind the four aligned frontal setae there are from front to back one pair (anterior discal), one pair (posterior discal) and a transverse postero-cephalic line with four setae. Antennal segments I and II similar in colour to head or in part darker than it, especially around the ventro-medial muscular impressions of segment I and near the end of segment II; antennal segment III smooth as in the proximal ones, with a short proximal part pale brown as in the proximal segments and progressively darkened to a dark brown or near-black apical ring; remainder of antenna progressively darkened and imbricated. Sensoria round and with thick walls; primary sensoria ciliate; secondary sensoria small, non-protruding and aligned, with the most proximal one at the end of the paler part of the segment. Rostrum surpassing middle coxae and darkening to apex. Ultimate rostral segment relatively narrow. Coxae and trochanters more-or-less pigmented than head and most of femora, which present a more-or-less extensive dorso-apical area darker than the remaining segments. Tibiae somewhat darker than the femora and with 1/7-1/8 of their length apical dark brown or almost black. Tarsi short and as dark as the distal end of tibiae and second segment with ventral setae. Setiferous sclerites on thorax and on pre-siphuncular abdominal segments small or very small, mostly unpigmented, near inconspicuous. Pre- and post-siphuncular sclerites absent. Intersegmental muscular sclerites absent. Spiracular sclerites small and light brown. Siphunculi progressively pigmented, brown to dark brown, cylindrical with enlarged proximal part, in most of the length a little wider than hind tibiae; transverse striae in the paler anterior half, scales progressively more marked on the distal portion prior to reticulation, which is ill defined; flange little marked. Setiferous sclerites on abdominal segments 6 to 8 and more-or-less light pigmented; those on VIII segment can be partially fused, without forming a continuous transverse sclerite. Subgenital plate pale, not darker than the ventral part of anterior abdominal segment and paler than anal plate and cauda, which are scarcely pigmented. Cauda lanceolate, with a marked proximal narrowing and more-or-less blunt at the apex; its setae are all similar in length and longer than the caudal width at the middle. Metric and meristic features in Table 2. Alate viviparous females and sexuales. Unknown. Etymology. The specific name nahuelhuapense is a supposed demonym of Nahuel Huapi lake, in neutral gender because Uroleucon is neutral. Bionomics. Aphids feed on the small stems of Adesmia boronioides Hook. f. (Fabaceae), which is its only known host plant. Sexuales are unknown, but the species is likely to be holocyclic, because of cold temperatures during winter. Geographical distribution. The new species is currently known in one locality of the Andean slopes of the Argentinean province of Neuqu��n, very close to the shore of the Nahuel Huapi lake. It is possible that the species occurs on the same plant species or on other species of Adesmia in other localities of similar altitude in Argentina or even in Chile. Molecular analyses. Amplification and sequencing of the tRNAleu-COII locus were performed successfully and resulted in divergent sequences for all South American taxa. Sequences obtained were deposited in GenBank (Table 1). Taxonomic discussion. M.P. Mier and J. Ortego had some difficulty in 2008 convincing reviewers of the manuscript describing U. adesmiae that the new species should be classified as Uroleucon, because its host plant was in Fabaceae, not Asteraceae or Campanulaceae, the usual host-plant families of Uroleucon (Mier Durante & Ortego, 2008). Furthermore, several morphological features of U. adesmiae were not typical of Uroleucon (almost total absence of setiferous sclerites as well as pre- and post-siphuncular sclerites). Justification of U. nahuelhuapense sp. n. as a Uroleucon is simpler because there is a great resemblance to U. adesmiae and U. payuniense Ortego & Nieto Nafr��a 2007 (see Mier Durante & Ortego, 2008), and because it shares the genus of host plant with U. adesmiae. This classification is further justified by genetic evidence. The tRNAleu-COII mitochondrial sequences confirm the correct placement of U. nahuelhuapense sp. n. (as well as U. adesmiae) within Uroleucon (Figure 2). Both species living on Adesmia form a cluster with other South American native Uroleucon and one Euro-Asiatic species, U. rapunculoidis (B��rner, 1939). While U. nahuelhuapense sp. n. and U. adesmiae are clustered most closely to each other, the magnitudes of their pairwise patristic distance (sum of branch lengths on the dendrogram) and Tamura-Nei distance are as great or greater than the distances between other established, valid species in the comparison (Table 3). Thus, these two taxa exhibit species-level genetic distances from each other and from other described Uroleucon, both South American and Northern Hemisphere species. It is generally accepted that the subgeneric classification of Uroleucon requires a thorough revision (see Blackman & Eastop, 2018). Our phylogenetic studies of Uroleucon in progress suggest that the South American species are not a monophyletic group, and that the subgenera as currently understood are not monophyletic (see also Moran et al., 1999). Until the necessary revision can be undertaken, however, it seems appropriate to place Uroleucon nahuelhuapense sp. n. in the subgenus Lambersius Olive, 1965, according to the concept of that subgenus in Nieto Nafr��a et al. (2007). Uroleucon nahuelhuapense sp. n. and U. adesmiae, the two species of Uroleucon living on Adesmia species, can be morphologically distinguished from one another by antennal pigmentation (darker in U. nahuelhuapense sp. n. than in U. adesmiae) and by different numbers of setae on the cephalic dorsum, on the ultimate rostral segment, on both dorsum and venter of abdominal presiphuncular segments, on genital plate and on cauda (see Table 2). Thirty species of Uroleucon have been recorded from South America: U. adesmiae Mier Durante & Ortego, 2008, U. aeneum (Hille Ris Lambers, 1939), U. ambrosiae (Thomas, 1878), U. bereticum (Blanchard, 1922), U. brevisiphon de Carvalho, 1998, U. chilense (Essig, 1953), U. compositae (Theobald, 1915), U. erigeronense (Thomas, 1878), U. essigi de Carvalho, 1998, U. eumadiae Delfino & Gonzales, 2005, U. garnicai Delfino, 1991, U. gochnatiae Delfino, 1994, U. gravicorne (Patch, 1919), U. jaceae (Linnaeus, 1758), U. littorale (Blanchard, 1939), U. macolai (Blanchard, 1932), U. malarguense Ortego & Nieto Nafr��a, 2007, U. mendocinum Mier Durante & Ortego, 2007, U. muermosum (Essig, 1953), U. nahuelhuapense sp.n., U. nuble (Essig, 1953), U. patagonicum Nieto Nafr��a & Seco Fern��ndez, 2007, U. payuniense Ortego & Nieto Nafr��a, 2007, U. petrohuense de Carvalho, 1998, U. pseudomuermosum de Carvalho, 1998, U. riojanum Nieto Nafr��a & Mier Durante, 2007, U. rudbeckiae (Fitch, 1851), U. sonchi (Linnaeus, 1767), U. tessariae Delfino, 1994 and U. tucumani (Essig, 1953). Four of them: U. aeneum, U. compositae, U. jaceae and U. sonchi are species wide-distributed and not native to the Americas, they can be easily separated to the others 26 species, which are South American or North American native species, because they have coxae wholly dark brown to black, as pigmented or nearly as pigmented as distal apices of femora, tibiae and most part of siphunculi, which are dark-brown to black sometimes with paler middle portion. In other 26 species coxae are yellowish brown to brown, less pigmented than distal part of siphunculi and usually less pigmented than the distal area of femora, and siphunculi are variably pigmented but if the middle part is not as dark as proximal and distal part then cauda is triangular shaped, not lanceolate. Most part of these 26 species are restricted to South America, only U. ambrosiae (Thomas, 1878), U. erigeronense (Thomas, 1878), U. gravicorne (Patch, 1919) and U. rudbeckiae (Fitch, 1851) are also known in North America. parentheses are exceptional data, or very exceptional if parentheses are duplicates. Bold characters in the Uroleucon adesmiae column indicate that the previously known corresponding limit has been modified with the new data. Arrows, single or double, indicate the most important characteristics to differentiate both South American species of Uroleucon living on Adesmia. ......continued on the next page The following key permits the separation of the Uroleucon species with relatively pale coxae, as it has been detailed before, recorded from South America. It is based on that by Nieto Nafr��a et al. (2007), which in turn was based on the key by de Carvalho et al. (1998); several disjunctive couplets have been simplified. Uroleucon littorale was described from a locality in the Argentine province of Entre R��os, it has not yet been collected and its original description is not too eloquent; it is very similar to U. tucumani, of which it can be synonymous in opinion by Blackman & Eastop (2018); it is not included in the key. The measurements are lengths unless otherwise indicated. In brackets are morphological data which do not have correspondence in the other proposition of the disjunctive, but which are useful to secure identification. Information on the distribution of each species has been actualized from our bibliographic registers. It includes countries for South America, regions for Chile and provinces for Argentina. Records from the Federal Capital of Argentina, Ciudad Aut��noma de Buenos Aires, are joined to records from the Buenos Aires province. The names of Chilean regions Ays��n del General Carlos Ib����ez del Campo, Libertador General Bernardo O���Higgins and Metropolitana de Santiago are simplified respectively to Ays��n, O���Higgins and Santiago. 1 Ventral hairs on proximal 2/3 of hind tarsi second segment small or atrophied. [Siphunculus 1.0���1.2 times cauda. Marginal tubercles present on abdominal segment 2 to 5. Alatae with protuberant secondary sensoria on antennal segment III. Green in life]. On composite species, mainly of genera Erigeron and Solidago. Probably Neartic in origin; Brazil, Colombia, Venezuela......................................................................................... U. gravicorne - Ventral hairs on proximal 2/3 of hind tarsi second segment similar in shape and length to others ventral hairs on this segment and on other tarsi.................................................................................... 2 2 Antennal segment VI processus terminalis longer than 1.2 mm. Siphunculi at least 2.3 times cauda, thin, brown with a pale proximal portion, and reticulated at most on 15% of total length. [Probably pale green with brown o brownish head and partially appendages and siphunculi when alive.] On Senecio smithii, Symphyotrichum squamatus and perhaps other composite. Chile: Ays��n, ��uble.............................................................................. U. nuble - Antennal segment VI processus terminalis shorter than 1.00 mm. Siphunculi shorter or longer than 2.3 times cauda, but if longer it has a different appearance or pigmentation or reticulation of those mentioned above........................ 3 3 Posterior part of cephalic dorsum (behind the discal two setae of vertex) with 6���11 setae............................. 4 - Posterior part of cephalic dorsum (behind the discal two setae of vertex) usually with 4 setae (the general feature in the genus)................................................................................................... 6 4 Cauda triangular or long-pentagonal and 0.22��� 0.30 mm. Abdominal segment 2 to 6 with 1���2 marginal setae each side [and 5���13 spinal and pleural setae]. Red with siphunculi dark brown when alive. [Siphunculi brown to dark brown in general often with a less pigmented middle portion]. On Mutisia spinosa. Argentina: Chubut and Neuqu��n............. U. patagonicum - Cauda lanceolate and 0.27���0.40 mm. Abdominal segments 2 to 4 with 3 or more marginal setae each side. Green or brownish green in life......................................................................................... 5 5 Siphunculi yellowish or very light-brown with paler proximal 1/4. Abdominal segments 2 to 6 with 6���12 marginal setae each side and 16���27 setae on spinal and pleural areas. Antennal segment VI processus terminalis at least 1.0 times antennal segment III. Siphuncular width at the base 2.4���4.3 times its width at the beginning of the reticulation, which is well sculptured and extends over 12.2���18.9% of its length. Ultimate rostral segment with 7���10 accessory setae. Cauda with 6���9 setae. Dorsoabdominal setae 50���60 ��m. Green in life. On Grindelia chiloensis. Argentina: Mendoza................... U. payuniense - Siphunculi homogeneous brown. Abdominal segments 2 to 6 with 3���6 marginal setae each side and 7���20 setae on spinal and pleural areas. Antennal segment VI processus terminalis at most 1.1 times antennal segment III. Siphuncular width at the base 1.6���2.9 times its width at the beginning of the reticulation, which is poorly sculptured and extends over only 8.0���13.4% its length, exceptionally to 14.3%. Ultimate rostral segment with 10���15 accessory setae. Cauda with 10���15 setae. Dorsoabdominal setae 35���45 ��m. Dark green to brownish green in life. On Adesmia. Argentina: Chubut and Neuqu��n...... U. adesmiae 6 Dorso-cephalic setae 18���36 ��m. [Greenish yellow to yellowish pale green in life. Siphunculi with paler proximal portion, more evident in alatae than apterae. Antennal segment III with 4���25 secondary sensoria on proximal 1/ 2 in apterae and 20���41 secondary sensoria in alatae]. On species of several composite genera, in South America Baccharis, Conyza, Erigeron, Gutierrezia, Haplopappus and Hysterionica. Nearctic introduced species; Brazil, Colombia, Peru, Venezuela; Argentina: Buenos Aires, C��rdoba, Entre R��os, Jujuy, Mendoza, Salta, San Luis, Santa Fe, Santiago del Estero; Chile: Maule, Santiago, Valpara��so...................................................................................... U. erigeronense - Distal setae on cauda variable in length, if shorter than other caudal setae then usually pointed. Dorso-cephalic setae 30���75 ��m.................................................................................................... 7 7 Ultimate rostral segment 0.21��� 0.27 mm and 1.5���1.8 times hind tarsi second segment.............................. 8 - Ultimate rostral segment 0.12��� 0.22 mm and 0.8���1.4 times hind tarsi second segment.............................. 9 8 Ultimate rostral segment 0.23��� 0.27 mm, with 6���10 accessory setae. Dark reddish to brown or black when alive. On Acrisione denticulata and perhaps on species of Senecio. Brazil; Chile: La Araucan��a, Los Lagos................... U. muermosum - Ultimate rostral segment 0.21��� 0.23 mm, with 18���24 accessory setae. Shiny green in life. On Madia chilensis and M. sativa. Chile: Santiago.............................................................................. U. eumadiae 9 Marginal tubercles protuberant, frequently on abdominal segment 5 and sometimes on abdominal segments 2 to 4. Ultimate rostral segment with 4���5 accessory setae. [Apterae with 14���26 secondary sensoria distributed on nearly whole length of antennal segment III.] Probably pale green in life. On unknown composite. Chile: Los Lagos.................. U. petrohuense - Marginal papillae absent on abdominal segment 5, if present on abdominal segments 2 to 4 then not protuberant. Ultimate rostral segment usually with 5 or more accessory setae......................................................... 10 10 Antennal segment VI processus terminalis at most 3.8 times antennal segment VI base. Siphunculi reticulated on at least 35% of their length and yellowish brown to light brown, like cauda, which is lanceolate. Dark-green with dark-brown head. On Baccharis, Gochnatia glutinosa, Gutierrezia, Hyaloceris cinerea and Senecio subulatus. Bolivia; Argentina: Catamarca, Jujuy, La Rioja, Mendoza, Salta, Tucum��n............................................................... U. gochnatiae - Antennal segment VI processus terminalis usually at least 3.8 times antennal segment VI base; if 3.1���3.9 times then siphunculi or cauda h, Published as part of Nafr��a, Juan Manuel Nieto, Von Dohlen, Carol D., Moreno-Gonz��lez, V��ctor, Ortego, Jaime & Durante, M. Pilar Mier, 2019, The species of Uroleucon (Hemiptera: Aphididae) living on Adesmia (Fabaceae) in Argentina, with the description of a new species, pp. 561-572 in Zootaxa 4555 (4) on pages 563-570, DOI: 10.11646/zootaxa.4555.4.7, http://zenodo.org/record/2585355, {"references":["Mier Durante, M. P. & Ortego, J. (2008) A new species of Uroleucon (Hemiptera: Aphididae) living on Adesmia (Fabaceae). Florida Entomologist, 91, 367 - 371. https: // doi. org / 10.1653 / 0015 - 4040 (2008) 91 [367: ANSOUH] 2.0. CO; 2","Nieto Nafria, J. M., Mier Durante, M. P., Ortego, J. & Seco Fernandez, M. V. (2007) The genus Uroleucon (Hemiptera: Aphididae: Macrosiphini) in Argentina, with descriptions of five new species. The Canadian Entomologist, 139, 154 - 178. https: // doi. org / 10.4039 / n 05 - 100","Blackman, R. L. & Eastop, V. F. (2018) Aphids on World's plants. An online identification and information guide. Available from: http: // www. aphidsonworldsplants. info (accessed 28 June 2018)","Moran, N. A., Kaplan, M. E., Gelsey, M. J., Murphy, T. G. & Scholes, E. A. (1999) Phylogenetics and evolution of the aphid genus Uroleucon based on mitochondrial and nuclear DNA sequences. Systematic Entomology, 24, 85 - 93. https: // doi. org / 10.1046 / j. 1365 - 3113.1999.00076. x"]}