Aphis (Aphis) hyalis Mier Durante, Nieto Nafría & Ortego, 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 : 451-454

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

Types. Holotype: apterous viviparous female ARG-1016- 2 (mounted with a paratype): ARGENTINA: MENDOZA: San Rafael: La Salina (34º 56" S, 68º 59' O, 1365 m), 24-November-1997, on Hyalis argentea, collection of the Universidad de León.

Paratypes: 84 apterous viviparous and 19 alate viviparous females collected on the same plant, collection of the Universidad de León ; of them: (1) same data as the holotype, 3 apterae and 6 alatae; (2) same locality as the holotype, 27-November-2012, J. Arneodo leg., 2 apterae and 2 alatae; (3) Maipú: Chachingo (33º 03’ S, 68º 45' O, 815 m), 18-November-2002, 19 apterae; (4) CATAMARCA: Belén (27º 37’ S, 67º 01' O, 1310 m), 4-November-2006, 28 apterae; and (5) SAN JUAN: Calingasta (31º 03’ S, 68º 28' O, 1650 m), 5-November-1996, 32 apterae) and 11 alatae .

Etymology. The specific epithet of Aphis hyalis sp. n. is the genus name of its host plant in genitive case.

Apterous viviparous females ( Fig. 6 , A–E). From 107 specimens (82 measured). When alive pale brown to brownish black, with white wax powder, sometimes abundant. In mounted specimens head brown or pale brown, with very small and scattered wrinkles. Frons straight or gently wavy. Clypeus slightly thickened and darker than cephalic dorsum. ANT.I–II smooth. ANT.III with 1–4 ST. URS with concave edges, apparently very sharp. TH somewhat rough, in some specimens with small and pigmented areas.ABD.1–6 membranous and with little obvious reticulation. Intersegmental sclerites small, as dark as the SIPH and darker than the small spiracular sclerites, and the ABD.7–8 transverse bands, which are sometimes fragmented. TH.1 MG TUB smaller than triommatidium, pale and slightly bigger than those on ABD.1 and ABD.7. COM MG TUB lacking. ST on ANT, TH, ABD and legs are thin, pointed and very pale, so that the small ones are almost inconspicuous. Coxae and trochanters light brown, like most part of femora. Tarsal formula, 3.3.2. SIPH subcylindrical, tapering to apex, very dark (they are the darkest part of aphid), and poorly ornamented. ABD.8 with 2((3)) ST. Genital plate with 2–3((6)) discal and 6–15 posterior ST. Cauda finger-shaped, with well-marked midway constriction with the central area and sometimes the apical area much paler than dark margins and, so that it contrasts with SIPH (remembering somewhat to A. gossypii ), and with 5–11 ST. Other qualitative features in “Common features of the new species”. Metric features in Table 3 .

Alate viviparous females ( Fig. 6 , F–G). From 19 specimens. ABD mostly membranous, ABD.2–6 with MG patches and ABD.7–8 with transverse bands, which are bigger than those in apterae. Cauda with 8–13 ST. ANT.III with 3–8 SEC SEN, big and well aligned. ANT.IV rarely with 1–2 small SEC SEN. Other qualitative features in “Common features of the new species”. Metric features in Table 3 .

Bionomics and distribution. The only known host plant of Aphis hyalis sp. n. is Hyalis argentea. The genus Hyalis D. Don ex Hook & Arn. ( Asteraceae ) is recorded for first time hosting an aphid species. There are no data available to establish the cycle of the species, which may be monoecious with sexual generation.

The new species is known in several places of Catamarca, San Juan and Mendoza, and has never been found more to the south.

Taxonomic discussion, diagnosis. Using the key for aptera of the Aphidina species known in South America by Nieto Nafría et al., (2019) Aphis hyalis sp. n. joins species in group 7. Apterous viviparae of many of these last species present segmental sclerotization on ABD.2–6, while those of A. hyalis sp. n. lack it. In this group there are species whose aptera have ABD. 2-5 membranous being possible to differentiate them from the new species by means of the ratio “ANT.VI.PT / ANT.VI.B”, which is less than 1.5 times in A. hyalis sp. n. and greater than 1.5 times in many of the others. Aphis martinezi Nieto Nafría, Ortego and Mier Durante, 1999 is the only species included in this group with apterae like those of A. hyalis in both mentioned features; they can be separated from each other by the values of the ratios “SIPH / cauda” and “ANT.III / ANT.VI.PT”, which respectively are 0.96–1.30 and 2.0- 2.8 in A. hyalis sp. n. versus 0.54–1.00 and 1.0– 1.7 in A. martinezi .

Figures

FIGURE 6. Aphis hyalis Mier Durante, Nieto Nafría & Ortego sp. n. A–E, apterous viviparous female; A, complete view, with details: TH.1 MG, ABD.1–2 MG; B, antennal flagellum; C, URS; D, cauda; E, HT.2. 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.