Micrallo 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 : 133-135

Taxon classification Animalia Lepidoptera Mimallonidae

Micrallo St Laurent & C. Mielke gen. n.

Type species.

Micrallo minutus St Laurent & C. Mielke, sp. n.

Etymology.

The genus name is based on the fact that the type species is remarkably small (micro- Latin), being one of the smallest in the family; + the ending -llo, which is shared with Mimallo Hübner, [1820], the type genus of Mimallonidae . The genus name is masculine.

Diagnosis.

Micrallo minutus is immediately distinguished from all described Mimallonidae by the small size (forewing length: 11.5 mm) combined with the silvery-gray ground color and smooth wing margins. Genitalia are also unique in both sexes. Males have extremely complex genitalia with semi-membranous valves and lateral pockets encasing the valves. The pockets are filled with thick, elongate deciduous setae. Female genitalia have bent apophyses anteriores and long, robust apophyses poste riores that are connected to paired pouches that open on either side of the papillae anales. In the single examined female, one (the left hand pouch when viewed ventrally) of the two pouches was completely filled with elongate, thick setae that appear to originate from the male. Cicinnus acuta (Schaus, 1892) is superficially similar, but much larger and lacks the club-like valves and differentiated setae in lateral pouches of the male genitalia.

Description.

Male.Head: Width roughly two thirds that of thorax, antenna bipectinate to tip; basal three rami pairs increasing in length from antennal base to roughly one fifth of antennal length where rami length is nearly constant for remainder of antenna until the final distal quarter, after which rami continuously decrease in length until terminus. Frons tan brown, labial palpus reduced, not extending beyond frons, second segment tufted, third segment highly reduced, indistinct. Thorax: Light gray, interspersed with darker petiolate scales, especially anteriorly. Legs: Gray brown, but tarsus darker brown, tibial spurs thin. Forewing dorsum: Forewing length: 11.5 mm, Wingspan: 23 mm, n = 1. Somewhat narrow, acutely triangular, apical third slightly concave, somewhat convex before tornus. Ground color light silvery gray, overall lightly speckled by dark petiolate scales. Antemedial line absent. Postmedial line light brown, angled outward from M3 to Rs3, angled sharply towards costa immediately after passing Rs4, line straight from M3 until posterior wing margin, outer edge of postmedial line lined with pale coloration, becoming darker at costa. Postmedial area darker graphite colored with pale pink-gray suffusion mesally. Discal mark black, oblique, somewhat ovoid in shape. Forewing ventrum: Similar to dorsum but browner medially, especially on costa; inner side of postmedial line with black suffusion, postmedial line more undulate than on dorsum. Hindwing dorsum: Coloration as for forewing dorsum, but browner, especially anteriorly; postmedial line more undulate than on forewing. Hindwing ventrum: Follows same pattern as forewing ventrum. Frenulum apparently absent or vestigial. Venation: Typical of Mimallonidae , very similar to Cicinnus melsheimeri but Rs3 + Rs4 much longer stalked. Abdomen: Short, extending slightly beyond hindwing tornus, almost tubular, coloration as for thorax but lighter gray ventrally. Genitalia: (Fig. 22), n = 1. Extremely complex; tegumen reduced, narrow, but with robust sclerotized margins. Vinculum circular, but heavily modified, variously connected to valves; pair of heavily sclerotized, curved, tusk-like structures originate near base of vinculum. Uncus reduced, bottle shaped. Gnathos as two unfused, outwardly sclerotized, inwardly membranous, elongated, tubular, mesally bent processes with two pairs of teeth mesally, two pairs basally. Valves highly modified, nearly absent, valves membranous proximal to vinculum, transitioning into club-shaped lobes distally, lobes extend nearly to apex of uncus. Base of valve with elongate, thick, deciduous, specialized setae, most of which contained in membranous fold laterally encasing valve-vinculum complex. Juxta partially fused to phallus, juxtal plate a reduced, roughly T-shaped structure embedded in anellus. Phallus simple, spade shaped (viewed dorsally), open dorsally, base with elongated, downward-angled process. Female.Head: As for male but antenna smaller overall with shorter rami. Thorax: As for male. Legs: As for male. Forewing dorsum: Forewing length: 11.5 mm, Wingspan: 22 mm, n = 1. As for male but browner, discal spot absent. Forewing ventrum: Similar to dorsum but browner, especially anteriorly and medially; inner side of postmedial line with black suffusion, postmedial line more undulate than on dorsum. Hindwing dorsum: As for male but browner. Hindwing ventrum: Follows same pattern as forewing ventrum. Frenulum apparently absent or vestigial. Abdomen: As for male but slightly more robust; sternite VIII with quadrate U-shape formed by thin sclerotized band spanning width and length of segment. Genitalia: (Figs 23, 24), n = 1. Papillae anales small, rounded, covered in fine setae. Apophyses anteriores thin, distal third angled dorsally; apophyses posteriores, robust, nearly straight, twice length and width of apophyses anteriores. Ductus bursae same length as segment VIII, ostium unsclerotized. Corpus bursae bag-like, without any sclerotized structures. Dorsal sclerotization of tergite VIII complex, ridged, forming posteriorly directed point. Lamella antevaginalis a very large plate, nearly of equal width as segment VIII, with deep, wide, mesal indentation forming ostium. Pair of specialized, lateral pouches on either side of papillae anales, pouches connected to apophyses posteriores. Viewed ventrally, right pouch filled with elongated, deciduous setae, left pouch empty.

Remarks.

An examination of Cicinnus acuta genitalia preparations (Franclemont genitalia prep. 1768 (CUIC) and St. Laurent diss.: 10-25-15:1) reveals minor simi larities in the shape of the phallus, wherein both species the phallus is rather flattened and spade shaped when viewed dorsally. Cicinnus acuta differs, however, in all other respects of genitalia structure, namely in the presence of well-defined valves, much shorter gnathos processes, and in the presence of sharp, almost pincer-like structures at the base of the valves.