Vanenga Schaus, 1928: 664

St. Laurent, Ryan A. & Herbin, Daniel, 2017, Revision of the genus Vanenga Schaus, 1928 (Lepidoptera, Mimallonoidea, Mimallonidae) with the description of a new species, ZooKeys 644, pp. 89-104 : 89-91

Vanenga Schaus, 1928: 664

Type species.

Perophora mera Dognin, 1924; Schaus 1928: 664, by original designation.

Diagnosis.

The Vanenga species are small, relatively plain mimallonids, but can be recognized by the short triangular forewings, straight, preapical or apical postmedial line, pale tan-orange ground color with varying degrees of pink coloration throughout the antemedial and medial areas, which may strongly contrast against the darker orange-brown submarginal area. The male genitalia define the genus by being rather simple with triangular valves, very long and narrow uncus, heavily sclerotized lobe-like gnathos projections, and a short, thick phallus with accessory spiny dorsal projections emanating from the juxta-phallus complex. These juxtal projections may be either long and narrow or short. The male genitalia are reminiscent of some species of Lacosoma Grote, 1864, as mentioned by Schaus (1928), but can be distinguished by the longer, narrower uncus and phallic structure. The female genitalia are unique in the absence of a clear lamella antevaginalis and by possessing a very broad ductus bursae, the papillae anales are also quite narrow and elongated, a combination of characters so far seen in no other female Mimallonidae .

Description.

Male.Head: Varying shades of orange, eyes very large, more than two thirds area of head; antenna coloration as for head, bipectinate to tip, though distal fifth of pectinations much reduced in size; labial palpus highly reduced, three segmented, palpus not extending beyond frons. Thorax: Straw colored or with pale pink scales, darker brown-orange scales present on prothoracic collar. Legs: Coloration as for thorax, but usually darker orange with rosy scales, vestiture fine. Tibial spurs short, curved, naked or dorsally clothed in scales. Forewing dorsum: Forewing length: 10-17 mm, wingspan: 23.0-32.5 mm. Rather short, not elongated, triangular, apically somewhat rounded or more angled. Ground color pale tan-orange, with varying degree of pinkish hue throughout, especially antemedial and medially, overall lightly speckled by dark brown petiolate scales, though may be nearly absent. Antemedial line absent or as faint brown wavy mark. Postmedial line nearly straight, preapical or apical, brown, fading after passing Rs3 or Rs4. Antemedial and medial areas concolorous, either orange-tan or pale pink. Submarginal area always darker than medial area, usually orange-brown with diffuse gray coloration along wing margin, petiolate scales more abundant submarginally. Discal spot may be absent, when present as small dark brown spot. Fringe orange-tan or with light pink hue. Forewing ventrum: Similar to dorsum but coloration of medial and submarginal areas more similar, more uniformly orange, becoming gray distally, usually also pink nearer to thorax. Discal spot always present, usually larger than on dorsum (when present there), sometimes more elongated, narrower. Postmedial line somewhat wavy, not as straight as on dorsum, preapical. Petiolate scales more abundant, widely dispersed. Hindwing dorsum: Rounded, coloration and patterning as for forewing dorsum, antemedial line absent, postmedial line straight or curved outward, submarginal area broader than on forewing dorsum. Hindwing ventrum: Follows same pattern as forewing ventrum. Frenulum as single bristle. Venation: Typical of Mimallonidae , similar to Lacosoma Grote, 1864 but distal margin of discal cell more slanted. Abdomen: Concolorous with thorax, ventrally with pair of darker gray lines of scales, distal tip of abdomen with tuft of black scales, usually upturned in well-preserved specimens. Genitalia: Simple; vinculum ovoid, ventrally with lightly sclerotized plate attached to VIII. Uncus simple, acutely triangular but very elongated and narrow, laterally smoothly curving or slightly indented mesally. Gnathos formed by two rather short, unfused arms, as either ovoid, flattened lobe with triangular tooth emanating from center or as more heavily sclerotized downwardly angled cylindrical protuberance. Valves triangular, somewhat angled distally. Valves with baseo-mesal indentation which usually bears patch of thick, heavy setae; base of valves extend past vinculum inward into body cavity as narrow singular or bifurcated extension loosely connected to diaphragm and juxta. Juxta fused to phallus, encircling it as oddly shaped saucer with dorsal spined projections superior to phallus, projections either short and heavily spined or more elongated, curved, and less heavily spined. Phallus short, cylindrical, not much longer than width of juxtal saucer. Vesica bag-like. Female.Head: As in male but antennae much smaller overall, pectination particularly shorter. Thorax: As in male though brown scales along prothoracic collar may be darker. Legs: As in male, but tibial spurs shorter. Forewing dorsum: Forewing length: 12-15 mm, wingspan: 25-31 mm. Sexual dimorphism reduced, male and female very similar. Maculation similar to male but wing broader, convex mesally, submarginal area broader, apex more sharply acute. Coloration generally more diffuse between antemedial, medial, and submarginal areas, less distinctly bicolored. Submarginal area grayer or pinker overall than medial area relative to males. Postmedial line usually more bowed outward, though may be just as straight as in males. Forewing ventrum: Similar to dorsum but darker or paler orange. Hindwing dorsum: Coloration and patterning as for forewing dorsum, similar to males but differing in same characters as forewing dorsum. Hindwing ventrum: Follows same pattern as forewing ventrum. Frenulum reduced, as multiple bristles. Abdomen: Concolorous with thorax, ventrally darker, distal tip with small tuft of elongated scales. Genitalia: Small overall, most characters somewhat atrophied, VIII as weakly sclerotized plate, posteriorly curved, laterally VIII more heavily sclerotized. Apophyses anteriores less than half-length of apophyses posteriores or absent, apophyses posteriores elongate, narrower than apophyses anteriories (when present). Lamella antevaginalis membranous. Ductus bursae broad, wrinkled, bag-like. Corpus bursae narrow, elongated, nearly twice length of VIII–IX. Papillae anales somewhat flattened ventrally, elongated and narrow.

Remarks.

The genus Vanenga seems to share a close affinity with Lacosoma considering the male genitalia ( Schaus 1928, St Laurent and Herbin pers. obs.) and small size of these moths overall. However, the female genitalia and external coloration, pattering, and wing shape are all quite distinct from Lacosoma . Compare our Figs 10-14 to male/female Lacosoma genitalia figured in Herbin and Mielke (2014), Herbin and Monzón (2015), and Herbin (2016).