Aphis (Aphis) sanrafaelina Ortego, Mier Durante & Nieto Nafría, 2022

Nieto Nafría, Juan M., Ortego, Jaime, Moreno-González, Víctor & Durante, M. Pilar Mier, 2022, The genus Aphis (Hemiptera, Aphididae) living on Asteraceae species in southern South America: Argentina and Chile, with five new species, Zootaxa 5183 (1), pp. 439-463 : 459-460

Aphis (Aphis) sanrafaelina Ortego, Mier Durante & Nieto Nafría sp. n.

Types. Holotype: apterous viviparous female (specimen ARG-551- 7 mounted with a paratype): ARGENTINA: MENDOZA: San Rafael: Cuesta de los Terneros (34º 42' S, 68º 34' W, 1800 m), on Tagetes mendocina , 7-February- 2000; collection of the Universidad de León. Paratypes: 194 apterous viviparous and 67 alate viviparous females, collection of the Universidad de León; of them: (1) same data as the holotype, 15 apterae; (2) ibidem, 1-November- 1997, 5 apterae; (3) ibidem, 9-March-1998, 20 apterae and 14 alatae; (4) ibidem, 9-November-1999, 19 apterae and 14 alatae; (5) ibidem, 13-October-2001, 3 apterae; (6) ibidem, 8-November-2001, 8 alatae; (7) Las Heras: Monumento Canota (32º 36' S, 68º 55' W, 1015 m), on Thymophylla pentachaeta , 30-November-2002, 28 apterae and 1 alate; (8) Luján de Cuyo (33º 05' S, 68º 58' W, 1050 m), on Th. pentachaeta , 30-November-2002, 6 apterae; (9) Tupungato: Cruz Negra (33º 26' S, 68º 58' W, 900 m), on Th. pentachaeta , 21-November-2002, 10 apterae; (10) NEUQUéN: Neuquén (32º 58' S, 68º 09' W, 300 m), on Th. pentachaeta , 8-February-2003, 31 apterae and 6 alatae; (11) LA RIOJA: General Felipe Varela: Cuesta de Miranda (29º 21' S, 67º 47' W, 2015 m), on Ta. mendocina , 26- November-2002, 14 apterae; (11) ibidem, 2-November-2006, 16 apterae and 18 alatae; (13) ibidem, 3-December- 2017, 21 apterae and 5 alatae; and (14) SAN JUAN: Talacasto (31º 05' S, 68º 38' W, 980 m), on Pectis odorata , 6- November-1996, 4 apterae and 1 alatae.

Etymology. The specific epithet sanrafaelina of the new species name is the Spanish demonym of San Rafael, which is the place with more specimens-type, in feminine gender because Aphis is a feminine noun.

Apterous viviparous females ( Fig. 9 A–E ). From 195 specimens (185 measured). When alive dull pale yellow to light green, usually with a reddish transverse strip immediately behind SIPH, and ABD.1–6 with shiny black spots in variable number. In mounted specimens, head brown and almost smooth. Frons slightly wavy with the middle part somewhat rough and darker than the rest of cephalic dorsum. ANT.I–II smooth. URS subrectangular in shape. ANT.III with 1–7 ST. TH and ABD with reticulation, but sometimes almost inconspicuous. TH.1 membranous or with scattered sclerites; TH.2 with wide spino-pleural and MG sclerites, often coalescing. TH.3 and ABD.1–5 with spino-pleural plate, irregularly edged and sometimes with some depigmented spots, it can be fragment into bands or disintegrate. ABD.6 usually with a spino-pleural band, sometime broken, and sometimes with small MG (postsiphuncular) sclerites. ABD.7-8 with small or very small sclerites, or rarely with very thin transverse bands. All mentioned segmental sclerites are as dark as the spiracular sclerites and are paler than intersegmental (muscular) sclerites. Notwithstanding the above, TH and ABD of specimens smaller than 1.3 mm (collected in February in Neuquén) are membranous or at most exhibit small and scattered sclerites. TH.1 MG TUB tall, as voluminous as the triommatidium and somewhat wider than those on ABD.1 and ABD.7; all of them with the proximal half thicker and somewhat darker than their distal half. COM MG TUB absent. ST fine, those on ANT, TH and ABD plus many on legs are blunt. Coxae as dark as or sometimes darker than trochanters and proximal part of femora. Tarsal formula 3.3.2. SIPH sub-cylindrical, very dark, rough (the imbrications of their margins are thick). ABD.8 with ((1))2((4)) ST. Genital plate paler than the anal plate and much paler than cauda and SIPH, with 2–6 discal and 2–12 posterior ST. Cauda long-triangular or faintly finger-shaped, because the midway constriction does not exist or is very little marked, as dark as SIPH, but can be paler on the middle than on the edges, and carrying 6–10 ST. Other qualitative features in “Common features of the new species”. Quantitative features in Table 5.

Alate viviparous females ( Fig. 9 , F–G). From 67 specimens. ABD.2-6 with MG patches and sometimes small and scattered spinal sclerites; ABD.7-8 with thin transverse bands or small or very small sclerites. ANT. III with 4–9 aligned SEC SEN. ANT.IV usually without SEC SEN, sometimes with 1 or 2, small. Other qualitative features in “Common features of the new species”. Quantitative features in Table 5 .

Bionomics and distribution. A. sanrafaelina sp. n. lives on plants of three genera of tribe Tageteae : Pectis L., Tagetes L. and Thymophylla Lag. , on stems and leaves. The genus Thymophylla is recorded for the first time hosting an aphid species. Sexual morphs are unknown, although it is possible that they exist. The specimens collected in Neuquén, which are smaller and less sclerotized than the others, could be aestivating apterae.

The new species in known in several places of La Rioja, Neuquén, Mendoza and San Juan, north and south of which it has never been found.

Taxonomic discussion, diagnosis. The ratio “URS / HT.2” of the apterous viviparous of Aphis sanrafaelina sp. n. does not allow following only one of the two proportions of couple I of the key to apterous viviparous females of Aphidina species known in South America by Nieto Nafría et al. (2019a), because this ratio varies between 0.8 and 1.1 times. Working on the identification of the specimens with this ratio lesser than or equal to 1 (approximately 90% of the measured specimens collected on Tajetes mendocina , and 40% of the specimens collected on Thymophylla pentachaeta or in Pectis odorata ), the couple N of the mentioned key would be reached, with two species: A. berberidorum Ortego & Mier Durante, 1997 and A. tropaeoli Nieto Nafría & Brown, 2019 . The ABD sclerotization of these species and A. sanrafaelina n. sp. is different; in addition, SIPH of A. berberidorum are usually shorter than cauda, and the cephalo-dorsal ST of A. tropaeoli are 27 µm long at least, while in A. sanrafaelina sp. n. SIPH are longer than cauda and the cephalo-dorsal ST are 21 µm long at most. Working on the identification of specimens with that ratio “URS / HT.2” bigger than 1 (which are a minority in the total of the type specimens), the new species is included in species group 7 of the key, with 26 species. A. sanrafaelina sp. n. differs from one or the other of the species of this group by: (1) the pigmentation of SIPH and cauda, (2) the ratio “ANT.VI.PT / ANT.VI.B”, (3) the shape of cauda, or (4) the sclerotization of TH and ABD.

Figures

FIGURE 9. Aphis sanrafaelina Ortego, Mier Durante & Nieto Nafría sp. n. A–E, apterous viviparous female; A, specimen poorly pigmented, with details: TH.1 MG, ABD.1–2 MG; B, specimen well pigmented; C, URS; D, SIPH; E, cauda. F–G, alate viviparous female; F, ABD; G, ANT.III and ANT.VI. The scales vary according to specimens or parts photographed; see measurements in Table 1.