Tostallo St Laurent & C. Mielke

St. Laurent, Ryan A. & Mielke, Carlos G. C., 2016, Three new genera of Neotropical Mimallonidae (Lepidoptera, Mimallonoidea, Mimallonidae) with descriptions of three new species, ZooKeys 566, pp. 117-143 : 118-120

Taxon classification Animalia Lepidoptera Mimallonidae

Tostallo St Laurent & C. Mielke gen. n.

Type species.

Perophora albescens Jones, 1912.

Etymology.

The genus name is derived from the toasted (tostus Latin) appearance of the white forewings, which is unique among Mimallonidae and reminiscent of toasted marshmallows; + the ending -llo, which is shared with Mimallo Hübner, [1820], the type genus of Mimallonidae . The genus name is masculine.

Diagnosis.

The monotypic Tostallo is remarkable among Mimallonidae in that the ground color is nearly white and the forewings rounded, a combination of characters seen nowhere else in the family. Male genitalia are unique in that the gnathos is formed by two large columnar structures with multiple invaginations and internal wrinkles. Female genitalia can be recognized by the wrinkled, setae covered accessory part of segment VIII, which encircles the papillae anales, as well as by the apophyses posteriores, which are hollow, almost balloon-like lobes, rather than thin rods as in other genera.

Description.

Male.Head: Width half that of thorax, light brown, eyes bordered posteriorly by dark-brown scales encircling head, forming dark mane; palpus not extending beyond frons, covered dorsally in darker brown scales; antenna opaque yellow, bipectinate to tip, rami increasing in length from antennal base to roughly middle of antennal length where rami length continuously decrease until terminus. Thorax: Pale tan brown, lighter near wing base, darker mesally, overall lightly speckled with darker petiolate scales. Legs: Color as for thorax, but tarsus light brown, petiolate scales present. Tibial spurs very thin, elongate, clothed in fine white scales. Forewing dorsum: Forewing length: 12-13 mm, avg. 12.5 mm, Wingspan: 23-26.5, n = 3. Subtriangular, outer margin convex, apex not pronounced. Ground color cream to white, overall lightly speckled by dark petiolate scales; outer margin fringed, grey. Antemedial line faint pale brown, somewhat wavy, especially near costa. Postmedial line dark brown, waxy, convex and mostly evident from costa to Rs3. Basal and medial areas proximately concolorous with thorax; medial area distally gray reaching inner margin towards wing base. Submarginal band darker, compressed, sometimes absent between postmedial line and marginal band. The latter grayish brown, delineated by an undulating line suffused with white distally. Discal spot marked by small, tan, crescent-shaped mark. Black patch of scales at apex extends to Rs3. Forewing ventrum: Similar to dorsum but more yellow brown, white and gray suffusions absent, submarginal and marginal bands lighter, postmedial line continuous, submarginal and antemedial lines absent. Hindwing dorsum: Coloration as for forewing dorsum, but lighter. Antemedial line brown, partially visible near inner margin. Postmedial line faintly marked, bordered by white distally. Submarginal band grayish brown. Marginal band lighter. Hindwing ventrum: Follows same pattern as forewing ventrum but discal mark absent. Frenulum a single, relatively-thick bristle. Venation: Typical of Mimallonidae , very similar to Cicinnus melsheimeri (Harris, 1841), but forewing M1 and M2 originate from cell nearer to R and CuA1 respectively, than to each other. Abdomen: Short, not exceeding hindwing tornus, stout, coloration as for thorax, ventrally pale. Genitalia: (Fig. 4) n = 4. Simple; tegumen reduced to slender rod. Vinculum box-like, not projected anteriorly. Uncus simple, subtriangular, truncated apically. Gnathos as two unfused, heavily-sclerotized, multiply-invaginated columnar structures with multiple internal folds. Valves short, irregularly shaped, somewhat triangular, truncated apically forming lobe, sclerotization weak mesally with heavily sclerotized fingerlike projection subapically. Juxta partially fused to phallus, separate portion of juxtal plate embedded in anellus. Phallus short, pistol shaped; flattened, open dorsally; base of phallus with short, anteriorly-curved lobe, vesica small, somewhat bag-like. Female.Head: As for male. Thorax: As for male. Legs: As for male, but tibial spurs slightly longer. Forewing dorsum: Forewing length: 14-16.5 mm, avg. 15.25 mm, Wingspan: 26-35 mm, n = 2. As for male but slightly longer, black patch of scales at forewing apex extended to Rs4 rather than Rs3. Forewing ventrum: Similar to dorsum but yellower brown. Antemedial line absent. Postmedial line continuous, submarginal band lighter. Hindwing dorsum: As for male but somewhat broader. Hindwing ventrum: Follows same pattern as forewing ventrum but discal mark absent. Frenulum apparently absent or highly reduced. Abdomen: As in male but more robust, sclerotized bands present ventrally on segment VIII. Genitalia: (Figs 5, 6) n = 2. Papillae anales setose, somewhat flattened ventrally, covered in short denticles from which very short setae originate. Apophyses anteriores very short, robust, flattened; apophyses posteriores as hollow, rounded, balloon-like lobes. Ductus bursae relatively long, corpus bursae bag-like with slight sclerotization terminally. Dorsal sclerotization of tergite VIII thin, folded inward, arc-like, with asymmetrical ridges on lateral sides of central arc. VIII encircles genitalia as thick, moderately sclerotized, setae covered, finely wrinkled structure, invaginated around entire circumference. Ostium unsclerotized. Lamella antevaginalis reduced, subtriangular, small notch apically.

Remarks.

Perophora albescens Jones, 1912 was described in the preoccupied genus Perophora Harris, 1841 ( Perophora Wiegmann, 1835 [ Tunicata]) despite the fact that another name, Ptochopsyche Grote, 1896, was proposed as a replacement well before Jones’s description. Both Perophora and Ptochopsyche are currently treated as synonyms of Cicinnus Blanchard, 1852 ( Becker 1996). However, Tostallo albescens comb. n. lacks the external and genital characters that are “characteristic” of the poorly defined genus Cicinnus (sensu Franclemont 1973, Herbin 2012, 2015, Herbin and Mielke 2014, Herbin and Monzón 2015), namely in that the forewings are not falcate and the valves of the male genitalia are simple rather than variously reduced as in Cicinnus melsheimeri , the type species of both Perophora and Ptochopsyche . Thus it is not appropriate to merely consider albescens within Cicinnus .

Schaus (1928), the last to completely revise the family, was unable to “identify” " Perophora albescens " and only re-iterated Jones’s description without assigning the species to a valid genus. Additionally, Becker (1996) did not list this species. Further compounding the ambiguity of the taxon albescens , neither sex of this species has been previously figured. While the validity of the species has never been questioned, Schaus’s inability to locate the holotype likely has led to this taxon being ignored or overlooked in all subsequent literature. Given the opportunity to re-examine Jones’s original specimens, including the holotype, and perform comparisons to all known Mimallonidae genera, it is readily apparent that Tostallo albescens comb. n. is unique among Mimallonidae and should be transferred to a new, monotypic genus. We therefore make this long overdue change in the present work, moving the name albescens from the preoccupied Perophora to a new genus, to solidify its uniqueness in the family. We provide figures of the holotype male, an additional male and female, as well as the genitalia of both sexes to allow for better recognition of this rarely reported enigmatic species.