Aphis (Hemiptera, Aphididae) species living on Baccharis (Asteraceae) in southern South America, with description of three new species Nafría, Juan Manuel Nieto Ortego, Jaime Brown, Paul A. López Ciruelos, Sara I. Durante, M. Pilar Mier Zootaxa 2019 2019-08-13 4656 1 153 167 Nieto Nafria & Mier Durante Nafría & Ortego & Brown & López Ciruelos & Durante 2019 [151,825,153,181] Insecta Aphididae Aphis Animalia Aphidomorpha 5 158 Arthropoda species conspicua sp. nov. Aphis  ( Fig. 2; Table 1)   Types.  Holotype. Apterous viviparous female(measured specimenARG-448 number 16, mounted with two paratypes):  ARGENTINA, Neuquén: Huilichesdep., Junín de los Andes( 39º 54’ S, 71º 04’ W,  800 m),  23-January-2000, on   Baccharissalicifolia,  Universidad de Leóncollection.  Paratypes: 214 apterous viviparous females[apt] and 1 alate viviparous female[al], Natural History Museum, Londonand  Universidad de Leóncollections.  ARGENTINA, Mendoza: Malargüedep., Arroyo Las Minas( 35º 27’ S, 69º 50’ W,  1960 m),  4-February-2000, on   Baccharissalicifolia, Ortego leg. (62 apt);  Malargüedep., La Colorada( 35º 30’ S, 69º 49’ W,  1810 m),  4-February-2000, on   Baccharissalicifolia(3 apt);  Malargüedep., Puesto Los Palacios( 35º 28’ S, 69º 49’ W,  1885 m),  28-November-2012, on  B. salicifolia, Arneodo& Ortego leg. (1 apt).  ARGENTINA, Neuquén: same data as the holotype(76 apt, 1 al);  Minasdep., Los Carrizos( 37º 03’ S, 70º 46’ W,  1150 m),  6-December-1998, on   Baccharissalicifolia, Ortego leg. (33 apt).  CHILE, Maule: Talcaprov., road to Paso Pehuencheat  2510 m( 35º 59’ S, 70º 24’ W),  2-February-2000, on   Baccharislinearis(41 apt).  Etymology.The specific epithet  conspicuais an adjective in nominative singular, and is feminine to agree with the genus name  Aphis, which according to the context can means: “visible”, “that is in view”, “that is seen”, and also “distinguished”, “remarkable”, “indisputable”, which is in relation to the set of characters that the viviparous females present that allows us to easily separate this species from the remaining South American  Aphisspecies.   FIGURE 2.  Aphis conspicuaNieto Nafría & Mier Durante,  sp. n.A–D, apterous viviparous female; A, specimen with intermediate dorsal sclerotisation; B, dorso-thoracic reticulation; C, marginal tubercles on metathorax (small one placed partially on the pigmented sclerite) and abdominal segments 1, 2 and 3; D, dorso-abdominal reticulation. E–F, Alate viviparous females; E, head plus a part of prothorax, and a part of metathorax plus abdomen; F, antennal segment III. The scales vary according to specimens or parts photographed; see measurements in Table 1.  Descriptions.Apterous viviparous females ( Figs. 2A-2D). From 215 specimens. When alive matt yellowish grey to matt black.  1.125 –1.849mmlong. Metric and meristic features in Table 1. Head, including clypeus and mandibular and maxillar lames and rostrum brown, sometimes with an irregular epicraneal line. Frons smoothly sinuate. Antennae usually six-segmented. Antennal segments I, II, V, VIand sometimes IVand a part of IIIas pigmented as cephalic dorsum, other parts of antennae brownish yellow. Antennal segments I, IIand most of IIIsmooth, IVwith small transversal striae and V and VIimbricated. Rostrum reaches nearly to the hind leg coxae. Ultimate rostral segment darker than proximal ones and carrying 2 accessory setae. Legs well pigmented, usually brown like cephalic dorsum except for a small proximal portion of femora, and ¾ proximal of tibiae that are brownish yellow. Tarsal chaetotaxy formula 3.3.2. Prothorax with very extensive sclerotisation, although never complete, rough and variably pigmented; mesothorax with marginal patches and a complete or fragmented transversal band, both two reticulated and well pigmented; metathorax with marginal patches also pigmented and reticulated. Dorsal abdominal sclerotisation is variable; in the most sclerotized and darkest specimens segments 1 to 5 have spinopleural bands that are very irregular in shape, frequently interrupted, brown and reticulated, plus small marginal sclerites that carry the tubercles, and segments 6, 8 and occasionally 7 have small setiferous sclerites. In less sclerotized specimens only a few small and dispersed spinal or pleural sclerites are present on presiphuncular segments. Intersegmental and spiracular sclerites on thorax and abdomen dark brown. Marginal tubercles very broad and low, on prothorax and on abdominal segments 1 and 7, as is usual in  Aphis, and also on all intermediate abdominal segments (rarely lacking on 6), frequently also on metathorax and sometimes on mesothorax; the diameter of those on prothorax as long as or longer than the eye diameter, those on the thoracic segments and on abdominal segments 5 to 7 are smaller than others but their maximum diameter is as long as or longer than the nearest seta. Siphunculi cylindrical, sometimes basally enlarged, with small flange, homogeneously as dark as or darker than the abdominal dorsum and imbricated. Genital and anal plates dark-brown. Cauda long-triangular, sometimes with a very slight proximal constriction. Setae in general very long, very slender and pointed. Alate viviparous females ( Figs. 2E-2F). From 1 specimen. Approximately 1.6 mmlong, (the specimen is broken). Very similar to apterous viviparous females, with the following differences in addition to different thoracic configuration: (1) antennae more homogeneously dark; (2) segment IIIrough and with 6 to 7 secondary sensoria, aligned over the entire length; (3) segment IVsometimes with 1 secondary sensorium, (4) marginal tubercles on prothorax and abdominal segments 1 to 7 protruding, cylindrical and flat domed; (5) much poorer dorso-abdominal sclerotisation. Metric and meristic features in Table 1.  Bionomics. Specimens of  A. conspicua  sp. n.live on the stems of plants of  Baccharis salicifolia(Ruiz & Pav.) Pers.and  B. linearis(Ruiz & Pav.) Pers.in compact groups. Alate females seem to be very rare. Sexual forms are not known so we are uncertain of their life cycle, but the species may be holocyclic.  Distribution. The area of distribution recorded for  Aphis conspicuais smaller than that of the other two species described here; the two localities placed at the ends of this area are 520 kmfrom each other in a straight line, nevertheless it is possible that its range is broader and overlaps with the area of distribution of its host plants,  Baccharis salicifoliais known in Argentinafrom the northern border to Santa Cruzand in a large part of Chileto Aysén, and  B. linearisis known in the Chilean Andes slopes from Antofagastato Aysénand in Argentinafrom San Juanto Chubut.  Taxonomic discussion.  Aphis conspicua  sp. n.can be differentiated from species of “group 5” in the key to apterous viviparous females of Aphidinaspecies recorded in Argentinaand Chileby Nieto Nafría et al. ( in press) (see “taxonomic discussion” of  A. fuentesifor the distribution and size of its marginal tubercles). Among these species, only  A. papillosahas very large marginal tubercles, but these tubercles are absent on meso- and metathorax, usually absent on abdominal segment 6 (only 16% of specimens have 1 papilla at least [Mier Durante et al., 2003]) and can be absent on one side of abdominal segment 5. In addition, both species can be separated by the length of siphunculi 0.9–1.4 times cauda and 0.11–0.27 mmin  A. conspicuaversus 0.4–0.9 times cauda and 0.07–0.16 mmin  A. papillosa, and also by the length of setae, which are longer in  A. conspicua, for example respectively in  A. papillosaand  A. conspicua,the setae on the vertex are 10–33 μm and 37–55 μm, on antennal segment IIIare 10–25 μm and 22–50 μm and on spinal zone of abdominal segments 2 or 3 are 10–31 μm and 35–57 μm. Differences between the various  Aphisspecies that live on  Baccharisspecies are shown in the identification key to apterous viviparous females at the end of the “taxonomic discussion” section of  Aphis fuentesi. 2413161235 5 158 2 1 holotype 2413161233 2000-01-23 Argentina 800 -39.9 Junin de los Andes 1166 -71.066666 Huiliches 5 158 1 Neuquen 2413161254 London Natural History Museum 5 158 2 2 paratype 2413161250 2000-02-04 Argentina 1960 -35.45 Arroyo Las Minas 1193 -69.833336 Malargue 5 158 1 Mendoza 2413161261 2000-02-04 1810 -35.5 La Colorada 1193 -69.816666 Malargue 5 158 1 2413161245 2012-11-28 1885 -35.466667 Puesto Los Palacios 1193 -69.816666 Malargue 5 158 1 2413161237 [696,1431,514,541] Argentina Neuquen 5 158 1 Neuquen holotype 2413161230 1998-12-06 1150 -37.05 Los Carrizos 1183 -70.76667 Minas 5 158 1 2413161229 2000-02-02 Chile 2510 -35.983334 Paso Pehuenche 1190 -70.4 Talca 5 158 1 Maule