Symmachia pena Hall & Lamas, new species
Creators: name: Hall, Jason P. W.
name: Lamas, Gerardo
Publisher: name: Zenodo
Year: 2007
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Lepidoptera
Riodinidae
Symmachia
Symmachia pena

description: Symmachia pena Hall & Lamas, new species
(Figs. 4; 8)
Description: Male: Forewing length 14.5 mm. Forewing elongate, with straight costal margin and slightly convex distal margin, four forewing radial veins; hindwing apex rounded and tornus very slightly pointed. Dorsal surface: Ground color of both wings dark yellow; both wings with broad black costal, distal and anal margins, black borders becoming broader on both wings in apex and tornus, black anal border on forewing tapering gradually to nothing near wing base, black costal border on both wings extending slightly into discal cell along its entire length, anal border on hindwing a more grayish black, distal margin of yellow on both wings slightly undulating, narrow pale yellow stripe along costal edge of hindwing (obscured in Fig. 4 by overlapping forewing); fringe on both wings entirely black. Ventral surface: Same as dorsal surface, but slightly paler and duller.
Head: First palpal segment and basal half of second segment brown, distal half of second segment and third segment predominantly pale yellow, palpi short; eyes black and bare, lateral scaling pale yellow; upper half of frons brown, lower half pale yellow; antennae approximately 75% of forewing length, antennal segments entirely black with a narrow and discontinuous nudum section lateroventrally, clubs black.
Body: Dorsal surface of thorax and abdomen dirty dark yellow, ventral surface of thorax predominantly black, ventral surface of abdomen a mixture of black and cream scales; a broad and continuous band of concealed androconial scales present dorsally across posterior margin of abdominal tergites four and five; forelegs pale yellow, mid- and hindlegs dark brown with brownish yellow scaling on tarsal segments.
Genitalia (Fig. 8): Uncus rectangular in lateral view, with a tiny posterior projection from dorsal middle of posterior margin, falces thickened at “elbow”, tegumen with a broad strip of desclerotization dorsally; vinculum a very narrow ribbon of even width, with a short and broad saccus ventrally that has a small round protrusion at anterior corners and a tiny anterior protrusion at middle of anterior margin; valvae consist of two sections, a Y-shaped upper section, with a broad, tapered and inwardly curved posterior projection and a narrow anterodorsal projection that extends over aedeagus to nearly connect with opposing valve, and an evenly broad, round-tipped, upwardly directed lower section, two valve sections joined at their anterior base by a narrow strip of sclerotization; aedeagus short, very broad and medially constricted, with anterior tip twisting sharply to right, and posterior section ventrally tapering to a narrowly pointed tip and dorsally forming two broadly rounded flanges divided medially by a deep indentation (aedeagus thus appearing Y-shaped in dorsal view), partially everted vesica consists of two components, a pad of ten to twelve (not all of which could be shown in Fig. 8) very large, posteriorly and inwardly pointed spines lining ventral margin of each dorsal aedeagal flange culminating in a very large spine that is fused to distal tip of flange, and two closely spaced, parallel, downwardly curved bands of numerous large spines through middle of vesica; pedicel short, broad and formed into two long, posteriorly projecting horns at lateral margins.
Female: Unknown.
Type material: Holotype ɗ, PERU: Junín, Quebrada Siete Jeringas, 1700 m, 11°12’S 75°24’W, 25 Aug 2003 (C. Peña) (MUSM).
No additional specimens of this species have been located in the world’s major collections.
Etymology: This species is named for the collector of the unique holotype specimen, Carlos Peña.
Diagnosis: This new species is a most interesting and unusual taxon because it appears to have no very close relatives among the symmachiine species discovered to date. One of the most important clues to phylogenetic placement in the Symmachiini is the arrangement of concealed androconial scales on certain male abdominal tergites (Harvey, 1987; Hall & Willmott, 1996; Hall & Harvey, 2002). This species has an unbroken band of scales on abdominal segments four and five, which is a common arrangement shared by most members of Phaenochitonia Stichel, 1910, Symmachia, Xynias Hewitson, 1874, Xenandra C. & R. Felder, 1865, Mesenopsis Godman & Salvin, 1886, and Pirascca Hall & Willmott, 1996. Most of these six genera are relatively small and well defined, and contain species that generally have rather homogeneous wing patterns and morphology. However, the large genus Symmachia, in addition to its core group of similar species that are closely related to the type species, currently contains a large heterogeneous assemblage of highly apomorphic species whose phylogenetic position within the tribe is unclear. Given that the wing pattern and morphology of pena do not closely match those of any described genus in the Symmachiini, Symmachia is therefore the most appropriate genus in which to temporarily place this new species until a generic-level phylogenetic revision of the tribe can reveal its true systematic status.
Symmachia pena cannot be confused with any other sympatric riodinid in the eastern Andes. Its simple wing pattern of large unbroken blocks of yellow on a black background is found in several species of Mesene, but only species of Mesenopsis also share its elongate wing shape. Particularly similar are M. bryaxis (Hewitson, 1870) and M. briseis Godman & Salvin, 1886, from west of the Andes. However, S. pena differs from these two species by having a slightly more compact wing shape, a slightly more rounded hindwing, more even black borders on both wings, a frons and palpi that are half brown and half yellow instead of entirely yellow, patagia that are covered with a mixture of brown and dark yellow scaling instead of bright yellow scaling alone, and an abdomen that lacks lateral and ventral yellow stripes. In addition, the male genitalia of S. pena are quite unlike those of Mesenopsis species, confirming the lack of any close phylogenetic relationship between the two taxa. All Mesenopsis species lack deeply bifurcate valvae, and have an evenly narrow aedeagus, without a pair of posterodorsal flanges, a dense patch of small spines at the dorsal base of the everted vesica instead of a long row of large spines beneath each aedeagal flange, and a single medial posterior projection from the pedicel instead of a pair of lateral projections.
Biology: Nothing is known about the biology of this very rare species, except that it inhabits wet montane forest at about 1700 m.
Distribution: Symmachia pena is currently known only from the type locality in the eastern Andes of central Peru.
description: Published as part of Hall, Jason P. W. & Lamas, Gerardo, 2007, Four new symmachiine taxa from the eastern Andes of Peru and Ecuador (Lepidoptera: Riodinidae), pp. 41-52 in Zootaxa 1533 on pages 50-51, DOI: 10.5281/zenodo.177751