Tabwecala robinsoni gen. nov., sp. nov., from Vanuatu and its systematic position in the ' Ophiusini - Poaphilini ' clade (Lepidoptera, Erebidae) Author Zilli, Alberto https://orcid.org/0000-0002-3416-8069 Natural History Museum, Life Sciences, Cromwell Road, SW 7 5 BD London, UK; a. zilli @ nhm. ac. uk; https: // orcid. org / 0000 - 0002 - 3416 - 8069 a.zilli@nhm.ac.uk text Nota Lepidopterologica 2021 2021-10-08 44 193 211 http://dx.doi.org/10.3897/nl.44.70359 journal article http://dx.doi.org/10.3897/nl.44.70359 2367-5365-44-193 EA6D65A049FE420FB0E55908EBF72D02 18B5BF4D68665E9EB5D8A8BF6B64641D Tabwecala gen. nov. Type species. Tabwecala robinsoni sp. nov. (described below), by present designation. Etymology. The generic epithet derives from the combination of "Tabwe-" (from Mt Tabwemasana in Espiritu Santo Island) and "-cala" (from the Greek "κᾰλή" , meaning "nice" ); it is feminine in gender. Diagnosis. The absence of sexual dimorphism in the labial palpi, the presence of two anterior spines on the male profemur, the absence of spines on male tibiae, the presence of an androteca on male mesotibia, the strongly modified male metatibia bearing a dorsal hair pencil, the tuba analis without scaphium and with a deep, hood-like scaphial pocket, and the sterigma projected posteriorly into a free end, represent altogether a combination of characters not seen, at the author's best knowledge, in other genera of the Erebidae . Description. Male (Fig. 1 ). Head . Large, feebly sunk into thorax, frons slightly bulged, unscaled at middle (scales evidently brushed off by labial palps after emergence as in numerous other Erebinae ), vertex roughly scaled, eye large, globular, antenna filiform, scape stout, barrel-like, covered by scales projected into small dorsal hood, pedicel small globular, flagellum consisting of short cylindrical, ventrally very shortly ciliate antennomeres, pilifer conspicuous, with long bristles, haustellum well developed, with tiny flat apical sensilla, labial palpus slender, upcurved, first joint roughly scaled, second joint compactly scaled, third joint long and thin, rod-like, two thirds as long as second, with no apical club. Figures 1, 2. Habitus of Tabwecala robinsoni gen. nov., sp. nov., from Vanuatu, Espiritu Santo, Mt Tabwemasana. 1. Holotype ♂; 2. Paratype ♀. Scale bar: 1 cm ( 1, 2. ). Thorax . Stout, both patagium and tegula broad and long, roughly scaled, meso-metanotum with hair-like scales, without crests; pectus conspicuously hairy. Wings broad; forewing vein R1 from middle of cell, areole present, splitting between Rs2 and Rs3 close to termen in apical area of wing, but topology of Rs branches from cell very variable (see dedicated paragraph below), M visible in outer half of cell, other veins as in other Erebinae , with CuA2 from before middle of cell; hindwing veins as in other Erebinae . Legs slender (Fig. 3 ); foreleg: profemur elongated, slightly wider at base and gradually tapered distally, with paired preapical spines, protibia not spined, barely shorter than femur, and feebly incrassate at middle, with epiphysis half length of tibia, protarsus conspicuously spined ventrally on tarsomeres I-IV, spines arranged into 3 rows, terminal spines of each tarsomere longest, spines replaced by bristles on tarsomere V, pretarsus with semi-circular arolium, onychia sharply bent, with midventral tooth, and pulvilli short; midleg: longest of the three legs, mesofemur long and slender, of almost uniform width, mesotibia greatly developed, longer and wider than mesofemur, its edges wrapping internally so as to originate a groove (androteca, cf. Berio 1955, 1959 , 1965 ) enclosing a long hair-pencil kept in place by flat scales, mesotibial spurs one terminal pair, mesotarsus slender, spines and bristles on I-V as in protarsus, pretarsus as in protarsus; hindleg: metafemur slender and of almost uniform width, 7/10 as long as mesofemur, metatibia not spined and greatly modified, very short, about 2/3 length of metafemur, and swollen distally and dorsally so as to show a teardrop outline with dorso-apical bulge (respecting tibio-tarsal axis) for insertion of conspicuous pencil of long, hair-like androconial scales, this leaning middorsally along basal tarsomere, metatibial spurs two pairs, long and flimsy, first pair from middle of metatibia, second pair from well before apex, mesotarsus with basal tarsomere greatly developed, thick and longer than tarsomeres II-V altogether, widest at base and gradually tapered apically, clothed externally with thin long setae and showing midventrally in its distal two thirds comb of long bristles, tarsomeres II-V and pretarsus as in fore- and midleg. Figures 3, 4. Legs of Tabwecala robinsoni gen. nov., sp. nov. 3. Male; 4. Female (this also with procoxa). Scale bar: 2 mm. ( 3, 4. ) Abdomen . Sternum A2 broad, subrectangular, with short, broad-based anterior apodemes, other segments of pregenital abdomen with subrectangular urotergites and urosternites, much wider than high, tergum A8 trapezoid, sternum A8 shallowly cleft on its posterior margin. Male genitalia (Fig. 5 ). Tegumen and vinculum robust, the latter shorter than tegumen and without inwardly produced saccus, valva oblong, with strongly sclerotised proximo-ventral portion, deriving from fusion between costal process and clasper, narrowly joined to sacculus, this produced into short saccular process, and dorso-distal membranous portion, which is broadly but shallowly corematous dorsally at base, where a conspicuous scent tuft is inserted. Uncus with dorsal process far from base. Tuba analis of complex configuration, dorsally membranous, showing distinct hood-like scaphial pocket (best seen in side view) above anus to accommodate tip of uncus. Juxta long, symmetrical, of the 'X' -type, articulated at very base of valvae. Phallus arched and compressed, with recurved foot-shaped coecum, showing small sclerotised platelet at base of vesica in distal excision of ventral edge of its shaft, vesica multi-lobed. Figures 5, 6. Genitalia of Tabwecala robinsoni gen. nov., sp. nov. 5. Male, paratype; 6. Female, paratype (sternum A7 on left). Scale bar: 1 mm ( 5, 6. ). Female (Fig. 2 ). Head . As in male, no sexual dimorphism detectable, including labial palpus, except for base of flagellum, slightly thinner, and periscapular scales, shorter and not forming hood. Thorax . Pro-metathorax and wings as in male, legs without the sexual secondary modifications seen in male (namely, profemural spines, mesotibial androteca, shortened and swollen metatibia bearing dorsal scent pencil and weak spurs, strongly developed basal segment of metatarsus with setae and comb), mesotibia irregularly spined externally, metatibia not spined, basal segment of metatarsus as long as tarsomeres II+III, with three rows of spines ventrally (Fig. 4 ); other features as in male. Abdomen . As in male but tergum A7 broad and high, approximately square-shaped, and sternum A7 greatly reduced to narrow and long subrectangular lodix plate (Fig. 6 ) overlapping ostium bursae. Female genitalia (Fig. 6 ). Complete sterigma present and of complex configuration, corresponding to broadly dilated midventral section of intersegmental membrane A7-A8 produced midventrally into stout, strongly sclerotised longitudinal outgrowth that terminates posteriorly into free end overlapping midventral sclerotisation which extends between from post-sterigmatal area to sternum A8; ostium bursae opening at approximately one third from anterior margin of sterigma. Bursa copulatrix with broad cervix and appendix anteriorly oriented originating from left of this. Ovipositor short, papillae anales soft, elongated, densely setose. Gonapophyses rod-like. Venational variation. Two different configurations regarding topology of forewing Rs veins, not linked to the sexes of specimens examined, have been found. As noted in the 'materials and methods' , these are reported here after a descriptive approach (italics between brackets) and an interpretative one (normal text and Figs 7 , 8 ). (1) [ Areole long; Rs1 from just beyond middle of areole; Rs2 and Rs3 long stalked, from upper distal corner of areole; Rs4 from lower distal corner of cell ] Rs1 and stalk (Rs2+Rs3) long stalked, from before end of cell, areole very long, bound superiorly by stalk (Rs1+(Rs2+Rs3)) and stalk (Rs2+Rs3), inferiorly by Rs (viz. cell) and Rs4, and closed by short anastomosis that from Rs4 reaches stalk (Rs2+Rs3) (Fig. 7 ). (2) [ Areole short; Rs1 from 4/5 length of areole; stalk of Rs2 and Rs3 shortly stalked with Rs4, from end of areole ] Rs1 and Rs2' stalked, from before end of cell, Rs2' free from bifurcation with Rs1 for short tract, then anastomosed and cojoined into short stalk ((Rs2 "+Rs3)+Rs4" ) which then separates into long stalk (Rs2"+Rs3) and Rs4", areole thus short, bound superiorly by stalk (Rs1+Rs2') and Rs2', and inferiorly by Rs (viz. cell) and Rs4' (Fig. 8 ). Figures 7, 8. Tabwecala robinsoni gen. nov., sp. nov., different branching patterns of veins from forewing areole (shaded light red) with interpretation of homologies (see criteria in Material and methods). 7. Long-areoled configuration; 8. Short-areoled configuration; M - medial; R - radial; Rs - radial sector; Sc - subcostal. Scale bar: 1 mm ( 7, 8. ). Distribution. The genus is currently known only from a restricted area of the Pacific (Vanuatu: Espiritu Santo). Systematic position. Features of the new genus indicate its position in tribe Poaphilini of the Erebinae ( Erebidae ), a group which is however morphologically ill-defined, as it will be reviewed in the discussion below.