Stuardosatyrus williamsianus ( Butler, 1868 ) (Argyrophorus)

Matz, Jess & Brower, Andrew V. Z., 2016, The South Temperate Pronophilina (Lepidoptera: Nymphalidae: Satyrinae): a phylogenetic hypothesis, redescriptions and revisionary notes, Zootaxa 4125 (1), pp. 1-108 : 68-69

Stuardosatyrus williamsianus ( Butler, 1868) (Argyrophorus)

( Figs. 3 C; 20J–L; 22)

Holotype: (female) BMNH #809625 (specimen examined)

Type locality: Puerto Hambre, Magallanes, Chile. However, Herrera & Pérez (1989) suggest, based on the dates of Darwin's visit (1–7 June 1834), that this is incorrect.

Other combinations:

Argyrophorus williamsianus — Heimlich (1972); D’Abrera (1988, p. 798); Peña & Ugarte (1997, p. 273); Pyrcz & Wojtusiak (2010).

Distribution. Found from central Santa Cruz Province in Argentina near Monte San Lorenzo south to the Straits of Magellan, and in Chile from Termas de Chillán to Puntarenas ( Herrera & Pérez, 1989) in late January to early February at 800–2300m ( Fig. 22 ).

Diagnosis. Southern species with coppery dorsal wings that are white at the costa of the forewing. Ventral forewing with a red-orange triangular postmedian band edged in dark chocolate brown that is widest toward the costa and narrowing to a rounded point between M3-CuA1. Apical M1-M2 ventral forewing ocellus is oval with a single, small, white pupil. Hindwing is oval with six lenticular ocelli in each cell from Rs to the anal vein that are neither ringed in yellow nor pupillated. Proximal border of the ventral hindwing postmedian band is irregularly scalloped, edged in dark chocolate brown, and bordered in white. Distal edge of the ventral hindwing postmedian band is a thin, dark chocolate line that curves nearly parallel to the termen and may cross through the ocelli.

Redescription. Head: Antennae 13–15mm, covered in chocolate brown scales with a longitudinal stripe of white scales, the club being mostly brown. Eyes are oval and naked, length a little less than 1.3 times width. Palps almost entirely white to cream with dark chocolate piliform scales on the ventral side. Terminal palp segment is conical. Thorax with black iridescent and tan piliform scales in the males; females not available for examination. Male foreleg tarsi fused into a single club-like segment without spines and midlegs with four rows of amber spines. Abdomen is dark coffee with sparse white scales on the ventral side.

Forewing ( Fig. 3 C): Wingspan 24–32mm. Termen entire and slightly convex and the discal cell curving only slightly inward at M1-M2. Forewings without androconia. Dorsal side is chocolate brown with a coppery sheen and white at the costa. Fringe scales are coppery brown layered on top of white. Dorsal postmedian band may appear as a series of triangular orange-red patches between the radials and CuA2 and the M1-M2 ocellus is visible as a dark chocolate oval patch. Ventral forewing is chocolate brown, white at the costa, with a small patch of black scales at the base. An orange-red patch appears just distal to the discal cell and adjacent the postmedian band, which is orange-red, edged in dark chocolate brown, and roughly triangular with the widest part toward the costa and narrowing to a rounded end between M3-CuA1. An R5-M1 ocellus may appear as a small, black, lenticular spot ringed in orange and a similar, round ocellus may appear between M2-M3. The apical ocellus between M1-M2 is oval, ringed in orange, and contains a very small white pupil.

Hindwing ( Fig. 3 C): Wing oval, termen entire and convex. Dorsal side similar in color to the forewing, but without orange-red patches. Fringe scales are as in the forewing and long, tan piliform scales appear at the base and over the discal cell, extending to the median and toward the inner margin. Ventral side from the base to the postmedian band is chocolate brown with a ripple pattern in dark coffee to black striations. Postmedian band is irregularly scalloped and black at the proximal edge with a white stripe adjacent the proximal border that fades to brown. Subterminal edge is a thin black line that may cross through the ocelli; terminal edge is black. A black lenticular ocellus appears in each cell between Rs and the anal vein.

Male genitalia ( Fig. 20 J–L): Uncus widest at the base, tapering gradually to a blunt terminus and slightly less than one and one-third times as long as the tegumen. Gnathos acute and a little more than one-third the length of the uncus. Pedunculus U-shaped and long. Saccus is deltoid and a little shorter than the gnathos. Aedeagus is acute at the proximal end, widening toward the middle and narrowing at the distal third before widening again at a cluster of several spines, narrowing just distal to the spines and widening slightly toward the distal end. Proximal end of the aedeagus is spatulate in the lateral view. Valvae are roughly rhomboid with the dorsal edge deeply serrated and the distal end acute.

Etymology. Named for John Williams Wilson (Juan Guillermos) (1798–1857), British-Chilean naval commander and founder of Fuerte Bulnes in the Straits of Magellan.

Specimens examined. Chile, Magallanes Province, (BMNH) Holotype female #809625; (MTSU) 4 males: JMC0301, JMC0306, JMC1003, JMC1004, (UJ) 6 males, 13 females; Argentina, Santa Cruz Province, (UJ) 3 males.

Figures

FIGURE 3. Composite habitus images of various monotypic genera. The left side of each specimen is the dorsal surface, the right side is the ventral surface. A, B: Argyrophorus argenteus Blanchard, 1852. male (BMNH # 789887) (A); female (BMNH # 789927) (B); C: Stuardosatyrus williamsianus (Butler, 1868) male (JMC 1003); D: Pamperis poaoeneis Heimlich, 1959 male holotype (scale bar = 1 cm; Photos provided by Ulf Buchsbaum, Zoologische Staatsammlung München); E, F: Neomaniola euripides (Weymer, 1890), showing variability of forewing shape, expanse of dorsal silver scales, and sizes and numbers of ocelli, in two specimens from Mazocruz, Puno, Peru (images from Cerdeña et al. 2014, open access).

FIGURE 20. Male genitalia of Punargentus and Stuardosatyrus species. See Fig. 2 for labels of parts. All drawings to the same scale. A – C: Punargentus lamna (Thieme, 1904) (CUIC) (uncus (A) and right valva (C) damaged); D – F: Punargentus chiliensis chiliensis (Guérin-Méneville, [1830) n. comb. (CH 32 - 2) showing ornamentation on the aedeagus (E); G – I: Punargentus monticolens (Butler, 1881) n. comb. (CH 24 A- 5); J – L: Stuardosatyrus williamsianus (Butler, 1868) (JMC 1003), showing ornamentation on the aedeagus (K).

FIGURE 22. Distribution of locality records for Argyrophorus argenteus, Pamperis poaoeneis and Stardosatyrus williamsianus.