Lepismalla St Laurent & Kawahara

Laurent, Ryan A. St & Kawahara, Akito Y., 2019, Reclassification of the Sack-bearer Moths (Lepidoptera, Mimallonoidea, Mimallonidae), ZooKeys 815, pp. 1-114 : 23-26

Lepismalla St Laurent & Kawahara gen. n. Figs 131, 132

Type species.

Cicinnus montagnaniae Herbin, 2012: 14, by present designation.

Etymology.

The name for this new genus is derived from the small, silvery coloration of the sole Lepismalla species, reminiscent of silvery Zygentoma in the genus Lepisma Linneaus. The ending -alla/-allo has been commonly applied in Mimallonidae . The genus name is feminine.

Diagnosis.

The single species of Lepismalla , L. montagnaniae comb. n., is recognizable by the almost complete lack of markings (except for faint irregular postmedial lines and heavy black discal marking) on the dorsal surface of the wings, which combined with the small size and falcate wing shape is unique in the family Mimallonidae . Genitalia are robust structures, with prominent gnathos arms that extend distally below the saccular margin of the valvae. In this way the gnathos arms are somewhat similar to those of related genera Procinnus Herbin and Micrallo St Laurent and C. Mielke, but extend much farther ventrally relative to the valvae. The basal valva arms typical of Druenticini are present, but highly reduced, and are flanked by setae covered regions of the sacculus. This genus lacks the claw-like sternite VIII extensions in the male genitalia which are typical of the related genus Procinnus , and has much shorter valvae tusks than either Procinnus or Micrallo .

Apomorphies.

(1) Large gnathos arms extend ventrally below saccular edge of valvae such that valvae appear dorsally to gnathos (Fig. 131I); (2) Base of valvae with tiny tusk-like arms (smaller than in any other Druenticini ) (Fig. 131II).

Description.

Male.Head: Light brown, eyes very large, occupying more than two-thirds area of head; antenna coloration light tan, antenna entirely bipectinate, distalmost quarter length of antennae with pectinations markedly shorter; labial palpus apparently two segmented, though a third segment may be present but small. Thorax: Light brown, lightly speckled with darker petiolate scales. Legs: Coloration as for thorax, vestiture thick, long. Tibial spurs elongate. Forewing dorsum: Forewing length: 14.5-16.0 mm, avg.: 14.6 mm, wingspan: 28-35 mm, n = 6. Triangular, margin concave mesally forming falcate apex. Ground color silvery gray and light brown, overall lightly flecked with dark brown petiolate scales. Antemedial line absent; preapical postmedial line faint, outwardly convex, consisting of numerous barely distinguishable individual dark brown petiolate scales. Discal mark present as irregular black splotch heavily contrasting against light ground color and otherwise largely unmarked surface. Fringe light brown, lightening to cream near tornus. Forewing ventrum: As for fore wing dorsum, but more brown than gray, anal region light tan, apex lighter gray than surrounding brown area; postmedial line slightly more well-defined; discal mark fainter than for dorsum. Hindwing dorsum: Coloration, patterning as for forewing dorsum, but discal mark much fainter to nearly absent. Fringe nearly white along most of wing margin. Hindwing ventrum: Following same pattern as forewing ventrum, but lighter overall, more of a continuation of light tan of anal area of forewing ventrum. Frenulum as single bristle, though difficult to see. Venation: Typical of Mimallonidae . Abdomen: Dorsal coloration as for thorax, ventrally lighter gray. Vestiture appearing thinner in comparison with thorax. Sternite of VIII with narrow pair of sclerotizations. Genitalia: (Fig. 131) n = 2. Vinculum ovoid, ventrally slightly pointed. Uncus simple, broad, triangular, distally narrowed to thin point. Gnathos massive, the most distinct aspect of the genitalia, gnathos heavily sclerotized with paired mesal arms which extend beyond and below saccular edge of valvae, gnathos arms distally and inwardly membranous, small tooth present at apex of each arm, gnathos arms fused mesally at base by narrow sclerotized band. Valvae small relative to gnathos, somewhat rectangular in shape, terminally with slight saccular lobe. Pair of small (length less than one third length of valvae), tusk-like curled sclerotized arms extend outward from saccular edge of valvae, tusk-like arms inwardly flanked by protruding setae covered sacculus. Juxta as thin sclerotization ventral to phallus forming connection with vinculum. Phallus curved when viewed laterally, viewed dorsally/ventrally phallus flattened distally with membranous opening such that phallus appears spade-like with sclerotized ring forming margins of spade shape, basal half of phallus as membranous sack. Female. Unknown

Remarks.

Lepismalla is described for the unique Amazonian taxon L. montagnaniae , which is so far outwardly and by male genitalia, unlike any other Mimallonidae , though is most similar to related genera Procinnus and Micrallo . In the original description, it was suggested that " Cicinnus " montagnaniae might be more properly placed in a new genus ( Herbin 2012). After examining genitalia of all genera in prior to and in preparation of the present work, it is clear the genitalia of L. montagnaniae do not conform to any other generic concept of Mimallonidae , and certainly this species is unique externally as well. However, the subfamily and tribal apomorphies provided by St Laurent et al. (2018a) for Druenticini are consistent with the general male genitalia characters seen in L. montagnaniae . Our morphological and ongoing molecular phylogenetic analyses also consistently place this taxon as sister to the druenticine genus Procinnus , within a robustly supported Druenticini clade (St Laurent et al. in prep.).

The shape of the phallus of Lepismalla is very similar to that of other druenticine genera Micrallo and Procinnus . The phallus in all three genera is flattened with a unsclerotized central region in the distal half, which is clearly visible from the dorsal or ventral aspect. These genera also display a membranous sack-like region along the basal dorsal half of the phallus, though the size of this structure differs between the genera. Paired sclerotizations of the VIII sternite typical of Druenticinae, including Micrallo and Procinnus , are present in Lepismalla , but are reduced to narrow sclerotized strips in the otherwise membranous intersegmental region. The silvery gray coloration of Lepismalla is a coloration scheme seen in almost all Druenticini genera (except the darkly colored Ulaluma and some Procinnus ), and the gnathos configuration is not unlike that of Procinnus and Micrallo , but simply more robust and ventrally farther reaching, such that in Lepismalla the gnathos arms actually reach below the saccular edge of the valvae. The basal valvae arms typical of Druenticini are present in Lepismalla , albeit greatly reduced.

Lepismalla montagnaniae is rare in collections, with only a handful of specimens known to us in global collections. Almost all examined material comes from the Amazon Rainforest, although one specimen, unfortunately destroyed in the fire at the Museu Nacional, Rio de Janeiro, Brazil, was from Mato Grosso do Sul, Brazil, in quite a different habitat on the border of Cerrado and Pantanal. An additional specimen in CPAC is from Distrito Federal in the Brazilian Cerrado. Future, finer scale, examinations of all known Lepismalla specimens may eventually reveal that this is not a monotypic genus, though it is certainly not diverse.