Uroleucon nahuelhuapense Nieto Nafría & von Dohlen, 2019

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, Zootaxa 4748 (3), pp. 548-560 : 550-553

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 .

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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.

Figures

FIGURE 1. Apterous viviparous females. A–C, Uroleucon nahuelhuapense Nieto Nafría & von Dohlen; D–I, Uroleucon australe Nieto Nafría & Mier Durante, sp. n.. A, D, habitus; B, G, apex of siphunculus; C, H, cauda; E, dorsal-cephalic seta; F, two setae on setiferous sclerites of abdominal segment 8; I, genital plate.

FIGURE 2. Uroleucon nahuelhuapense Nieto Nafría & von Dohlen, alate viviparous female

FIGURE 3. A–C Uroleucon nahuelhuapense Nieto Nafría & von Dohlen; D–F Uroleucon australe Nieto Nafría & Mier Durante, sp. n.. A, D, oviparous females, habitus; B, E, males, habitus; C, oviparous female, setae on setiferous sclerites of abdominal tergite 6; F, male, several dorsal setiferous sclerites of five successive abdominal tergites unfocused setae being ventral.

Tables

TABLE 2. Metric and meristic features of U. nahuelhuaense: apterous viviparous females (apt.viv.fem.), alate viviparous females (al.viv.fem.), oviparous females (ov.fem.) and males (males). Numbers in parentheses are exceptional data, or very exceptional if parentheses are duplicates. Bold characters indicate that the previously known corresponding limit has been modified with the new data. NOTES: (TS), type specimens; (NS), specimens collected in 2019.

Feature	apt.viv.fem. n=27 (TS) +10 (NS)	al.viv.fem. n=9 (NS)	ov.fem. n=16 (NS)	males n=14 (NS)
body (cauda included) [mm]	2.38 –3.53	2.88–3.38	2.38–3.20	2.20–2.48
body / siphunculus [times]	3.40–5.11	3.85–4.62	3.49–4.53	3.81–5.06
setae on head dorsum behind the anterior discal pair [number]	(3)6((8))	4–8	4–5	3–6
setae on vertex [μm]	38–63	35–58	45–65	43–55
setae on vertex [times D]	0.9–1.6	0.9–1.5	0.9–1.7	1.2–1.5
antenna [mm]	2.54– 3.39	3.31–3.67	2.69–3.39	2.54–3.05
antenna / body [times]	0.8– 1.2	1.0–1.2	1.0–1.2	1.2
antennal segment III [mm]	0.66–0.91	0.86–0.95	0.69–0.88	0.67–0.83
setae on antennal segment III [μm]	28–45 (53)	35–48	30–45	38–45
setae on antennal segment III [times D]	0.7– 1.4	0.9–1.3	0.8–1.2	1.0–1.3
secondary sensoria on antennal segment III [number]	2–11	10–22	3–11	16–50
antennal segment III with secondary sensoria [%]	24– 53	52–82	29–50	~95
antennal segment IV [mm]	0.48– 0.78	0.68–0.86	0.54–0.72	0.56–0.70
secondary sensoria on antennal segment IV [number]	//	//	//	8–25
antennal segment V [mm]	0.39–0.59	0.55–0.64	0.44–0.68	0.38–0.52
secondary sensoria on antennal segment V [number]	//	//	//	2–11
antennal segment VI base [mm]	0.15–0.20	0.16–0.22	0.15–0.19	0.13–0.17
antennal segment VI processus terminalis [mm]	0.55– 0.80	0.73–0.86	0.58–0.79	0.51–0.66
antennal segment VI processus terminalis / antennal seg- ment III [times]	0.7– 1.0	0.8–0.9	0.8–1.1	0.7–0.9
antennal segment VI: processus terminalis / base [times]	3.2– 4.6	3.8–5.1	3.1–4.9	3.5–4.6
ultimate rostral segment [mm]	0.17– 0.21	0.19–0.21	0.18–0.21	0.17–0.19
ultimate rostral segment / antennal segment VI base [times]	0.9– 1.3	0.9–1.2	1.0–1.3	1.1–1.4
ultimate rostral segment / second segment hind tarsus [times]	1.1–1.4	1.1–1.3	1.1–1.4	1.1–1.3
ultimate rostral segment / its basal diameter [times]	2.2–3.4	2.5–3.5	2.6–3.3	2.4–3.2
setae on ultimate rostral segment, accessory [number]	6 –9	6–8	6–9	5–9
hind femur [mm]	0.85–1.12	1.05–1.15	0.83–1.08	0.85–1.00
hind tibia [mm]	1.50–2.03	2.00–2.15	1.55–1.95	1.58–1.83
scent plates on a hind tibia [number]	//	//	24–77	//
scent plates on both hind tibiae [number]	//	//	52–138	//
scent plates, occupied length of hind tibia [percentage]	//	//	29–49	//
setae on first tarsal segments [number]	(3,4)5	5	5	5
second segment hind tarsus [mm]	0.13–0.17	0.15–0.17	0.14–0.17	0.14–0.17
setae on abdominal segment 2 to 5, dorsal, total [number]	12– 18(21)	20–38	13–19	13–21
setae on abdominal segment 2 to 5, marginal each side [number]	2– 4	6–13	3–4	2–7
setae on abdominal segment 2 to 5, spinal & pleural [number]	6– 13	7–13	6–11	6–10

TABLE 2. Metric and meristic features of U. nahuelhuaense : apterous viviparous females (apt.viv.fem.), alate viviparous females (al.viv.fem.), oviparous females (ov.fem.) and males (males). Numbers in parentheses are exceptional data, or very exceptional if parentheses are duplicates. Bold characters indicate that the previously known corresponding limit has been modified with the new data. NOTES: (TS), type specimens; (NS), specimens collected in 2019.