Inbio hilara

Nakahara, Shinichi, Janzen, Daniel H., Hallwachs, Winnie & Espeland, Marianne, 2015, Description of a new genus for Euptychia hilara (C. Felder & R. Felder, 1867) (Lepidoptera: Nymphalidae: Satyrinae), Zootaxa 4012 (3), pp. 525-541 : 529-532

Description of Inbio hilara .

MALE: Forewing length 15.0– 17.5mm (n=5).

Head ( Figs 2 c, 4d): Eyes light brown, posteriorly darker, sparsely hairy, hairs somewhat brownish; labial palpi second and third segment covered with white scales laterally, black scales dorsally, ventrally adorned with long black hair-like modified scales 3–4 times as long as second segment width, second segment about as long as eye diameter, three times as long as third segment; antennae approximately half as long as forewing, with 33–37 segments (n=3), pedicel about half as long as scape, flagellum lighter than scape and pedicel, with distal 13–15 segments composing club.

Thorax: Dorsally covered with white scales and long multi-colored hair-like modified scales; ventrally covered with white scales and white hair-like modified scales.

Legs ( Figs 2 d, 4b): Foreleg somewhat elongate, tibia and femur about the same length, tarsus slightly shorter; tarsus and tibia of meso- and metathoracic leg adorned with spines ventrally, meso- and metatibial spurs present at distal end of tibia.

Abdomen ( Fig. 2 e): Abdomen approximately four-fifths as long as hindwing inner margin, long creamcolored hair-like modified scales present around dorsal surface of eighth abdominal segment; eighth tergite reduced, approximately covering anterior fifth of dorsal abdominal segment; eighth sternite reduced, approximately covering anterior fourth of ventral abdominal segment; posterior third of dorsal surface of eighth abdominal segment and posterior half of ventral surface of eigth abdominal segment exhibit slight degree of sclerotization.

Genitalia ( Figs 3 a–c): Tegumen somewhat elongate in lateral view, dorso-anterior margin curved, ventral margin flattened; uncus narrow, curved, without setae, slightly tapered posteriorly, almost equal to tegumen in length; brachium about half as long as uncus, thickened at base, gradually tapered towards posterior end, pointing outwards in dorsal view, distal half slightly curved in lateral view; ventral arms of tegumen medially divided, middle section curved; appendices angulares present; saccus short, dorsal arms of saccus combined with ventral arms of tegumen; juxta present; valva positioned at approximately 30º angle to horizontal; basal two-thirds of valva somewhat elliptical in lateral view, ventral margin almost flattened, dorsal margin concave, distal third tapered anteriorly, hooked upwards in lateral view; aedeagus straight, slightly shorter than combined length of uncus and tegumen, open anterodorsally, cornuti absent.

Wing venation ( Fig. 4 a): Forewing recurrent vein short, about the same length as horizontal region of m1-m2; forewing cubital vein with basal region slightly inflated; hindwing humeral vein present.

Wing shape: Forewing somewhat triangular; hindwing rounded.

Wing pattern ( Fig. 2 a, b). Dorsal surface: Forewing ground colour greyish brown, distally darker, slightly translucent, thus subtly revealing ventral dark bands and ocelli; hindwing ground colour same as forewing, darkbrown undulating submarginal band extending from apex to tornus, area distal to submarginal band darker; dark brown undulating marginal band extending from apex to tornus; tornus with white coloration extending towards 3A; black round spot in cell Cu1.

Ventral surface: Forewing ground colour greyish brown; discal band reddish-brown, straight, extending from Sc to 2A, crossing discal cell in a slightly inward diagonal direction; postdiscal band primarily orange, with reddishbrown termini, almost parallel to discal band, broader than discal band, extending from R2 towards inner margin until reaching 2A; submarginal band narrow, dark brown, sinuate, somewhat lunulate; marginal band parallel to submarginal band, concolorous, slightly thinner, undulating; fringe greyish brown; ocellus in cell M1 extending across M1 and M2, black with one silver pupil in center, with yellowish ring; ocellus in cell M2 smaller, with slightly darker ring, grey with one silver pupil in center, anterior margin fused with posterior margin of larger ocellus; ocellus in cell M3 same size and colour as that in cell M2, anterior margin fused with posterior margin of cell M2 ocellus; all ocelli surrounded by dark grey shading that extends and broadens towards the costal margin, area delimited by ocelli and submarginal band creamy-yellowish; orange patch in cell Cu1 extending to orange region of postdiscal band. Hindwing: Ground colour same as forewing, area between postdiscal band and submarginal ocelli slightly whitish; reddish-orange discal band almost same width as forewing band, nearly straight, extending from costal margin to inner margin; postdiscal band parallel to discal band, concolorous, wider, extending from costal margin to inner margin, bent towards base in cell 2A; narrow submarginal band undulating, somewhat lunulate, rather straight towards tornus, broadens beyond Cu2 and exhibits same color as discal and postdiscal band; marginal band same colour as submarginal band, undulating, thinner than submarginal band, slightly broadening and possessing same colour as discal and postdiscal band right before 2A; fringe greyish; cells Rs, M1, and Cu1 each with ringed, submarginal ocellus identical in coloration to forewing ocellus in cell M1, ocellus in Rs relatively small, ocellus in cell Cu1 relatively large, extending across Cu2; cells M2 and M3 each with ocellus, identical to forewing ocelli in cells M3 and M2, these five ocelli not touching neighbouring ocelli; all ocelli surrounded by dark grey, especially extending basally, broadening towards cell Cu1; area delimited by dark grey shading and submarginal band creamy-yellowish.

FEMALE: Forewing length 15.5–19.0mm (n=14) Similar to male, except as follows: Forewing shape rounder; area basal to submarginal band of dorsal hindwing white; ground colour of ventral surface somewhat whitish; first and second subsegments of foretarsus ( Fig. 4 c) indistinct, almost fused, pair of spines present on second and third segments; seventh sternite weakly sclerotized relative to the more anterior sternites; intersegmental membrane between seventh and eighth abdominal segments partially folded ventrally, posterior half sclerotized, covering ostium bursae in ventral view.

Genitalia ( Figs 3 d–e): Lamella antevaginalis unsclerotized, sclerotized plate present in lateral region of eighth abdominal segment, tapered towards ventral surface; ductus bursae membranous, origin of ductus seminalis approximately one-seventh length of distance from ostium bursae to beginning of corpus bursae; corpus bursae oval in dorsal view, extending to fifth abdominal segment, with two signa.

Distribution. Based on the locality data obtained from museum specimens, this species, the only species included in the genus, is distributed from southern Mexico to western Ecuador. However, we were unable to locate specimens from Guatemala, Belize, El Salvador, and Honduras. It is common in mid-elevation rain forest edges in Area de Conservación Guanacaste in northwestern Costa Rica.

Immature stages. Third, fourth, and fifth (final) instar larvae of the type species are figured in figure 5.

Food plant of caterpillars. The caterpillars of the type species of this genus, I. hilara , feed on the small vinelike bamboo Rhipidocladum racemiflorum (Poaceae) ( Janzen & Hallwachs 2014).

Figures

FIGURE 2. Inbio hilara: a adult male (dorsal surface on left, ventral surface on right); b adult female (dorsal surface on left, ventral surface on right); c head in lateral view; d tibial spur on metathoracic leg; e male abdomen in lateral view (FLMNH- MGCL Voucher No. 191028, 191040). Scale bar indicating 1 cm for a and b, 1 mm for c – e.

FIGURE 3. Genitalia of I. hilara: a male genitalia in lateral view; b male genitalia in dorsal view; c aedeagus in dorsal view; d female genitalia in ventral view; e female genitalia in dorsal view (FLMNH – MGCL Voucher No. 191037, 191044). Scale bar indicating 1 mm.

FIGURE 4. Drawings of external morphology of I. hilara: a male wing venation; b male foreleg (tarsus, tibia, and femur); c female foretarsus; d male labial palpi (third and second segments); e female labial palpi. Scale bar indicating 1 cm for a, 1 mm for b – e.