Pseudonascus Austin, 2008

Austin, George T., 2008, Hesperiidae of Rondônia, Brazil: Taxonomic comments on “ night ” skippers, with descriptions of new genera and species (Lepidoptera: Eudaminae), Insecta Mundi 2008 (29), pp. 1-36 : 25-26

GENUS Pseudonascus Austin , new genus

Type species: Papilio paulliniae Sepp, [1842]

Description. Male: medium-sized (FW length = 21-23 mm), wing shape similar to Nascus , but forewing less produced with rounded apex and narrow costal fold (39% of forewing length), termen slightly convex anteriorly and then vaguely concave posterior to CuA 2; hindwing rounded, weakly lobed at tornus; dorsal color brown with ochreous overscaling basad on forewing and extending nearly to termen on hindwing, pale ochre macules (some translucent) of forewing include three contiguous on disk (discal cell, M 3 -CuA 1, CuA 1 -CuA 2), one on costa anterior to macule in discal cell, and four subapical; venter similar to dorsum, ochreous scaling less extensive, anal margin on forewing paler, with vague discal dark smudges on hindwing; palpi not particularly robust, quadrate in dorsal view, rounded in lateral view, third segment extending prominently beyond scaling of second segment; antennae 57% of forewing length curved to apiculus shorter than club length, nudum of 19-22 segments; legs with moderately dense and short hairlike scales on posterior edge, mid-tibia not spined and with single pair of spurs, hind tibia with two pairs of spurs; ventral hindwing with rounded groove lined with pale yellow scales on basal 1/2 of wing along vein 2A, groove gradually expanding and becoming shallower towards termen, anterior edge of groove with short hair tuft, long recumbent hair-like scales above groove on dorsal surface.

Male genitalia ( Fig. 117 ): tegumen short and quadrate (especially in dorsal view) without caudal processes; uncus hooked downward, cephalic end extending above the plane of caudal end of tegumen, gradually tapering in dorsal view, undivided; gnathos short, relatively well-developed, divided; valva short and stout, harpe tapering to blunt caudal end; aedeagus longer than valva, moderately robust, slightly curved; cornuti consisting of three bundles of large spikes and a series of smaller spikes.

Female: dark brown with ochreous overscaling less extensive than on male, larger than male (FW length = 22-26 mm), wings more rounded, forewing less produced, hindwing quadrate, produced at vein CuA 1, no costal fold on forewing or groove on ventral hindwing, macules on forewing white (some translucent), discal macules diagonal, aligned in costal cell, discal cell, CuA 1 -CuA 2, and CuA 2 -2A, four subapical macules, no or minute macule in M

3

-CuA

1

.

Female genitalia ( Fig. 124 ): lamella postvaginalis broad and relatively short, shallow V-shaped notch at center of caudal edge; central portion of lamella antevaginalis U-shaped, the arms broad, caudal edge of each with sharply pointed tooth-like projection on outer edge exceeding caudal margin of lamella postvaginalis; antrum broad with internal sclerotization; ductus bursae broad, oblong, narrowing slightly before oblong corpus bursae.

Distribution. Pseudonascus occurs from Mexico to Bolivia and Brazil ( Godman and Salvin 1879 -1901; Draudt 1921 -1924; Hoffmann 1941; Evans 1952; Steinhauser 1975; de Jong 1983; de la Maza and de la Maza 1985; Cock and Alston-Smith 1990; de la Maza et al. 1991; Mielke and Casagrande 1991, 1997; Lamas 1994; Robbins et al. 1996; Warren 2000; Vieira 2004).

Etymology. The name reflects the misplacement of the type species of Pseudonascus in Nascus .

Diagnosis and discussion. Papilio paulliniae clearly does not belong in the genus Nascus (type species Papilio phocus Cramer, 1777 ), yet it possesses certain similarities to this and other genera of Evans’

(1952) group “D”. Superficially, the species is similar to Nascus in pattern and has similar sexual dimorphism. The forewing is less produced and more rounded than that of Nascus , the hindwing is not as elongate and is more rounded at the tornus, and the costal fold is of similar proportional length (38-43% forewing length on Nascus ). The antennae of Pseudonascus are proportionally longer than are those of Nascus (antennae of Nascus 50-53% of forewing length) and the nudum is shorter (25-27 segments on Nascus ). Nascus has a similar tuft on the edge of the groove on the ventral hindwing, but this is further from the wing base than it is on Pseudonascus . The tibiae of Pseudonascus are less densely “haired” than those of Nascus and the palpi are more quadrate in dorsal view (more or less rounded on Nascus ), shorter in lateral view (elongate and gradually curving on Nascus ), and with the third segment more protruding (only extending a short distance beyond the scales of the second segment on Nascus ).

Female genitalia perhaps indicate alliance of Pseudonascus to Nascus as their general form is similar to Nascus , but they lack the rosette at the terminal end of the antrum, the antrum joins directly with the caudal end of the ductus bursae, and the lamellae are broader than long. Male genitalia of Pseudonascus are notably different from those of Nascus with their short and quadrate tegumen lacking caudal processes, the bent uncus, the relatively well-developed and divided gnathos, and the blunt valvae.

Figures

Figure 117-120. Male genitalia of Pseudonascus and Nascus (from BRAZIL: Rondônia). Structures shown are lateral, dorsal, and ventral views of tegumen, uncus, gnathos, and associated structures; lateral internal view of right valva; lateral view of aedeagus and associated structures; and ventral view of transtilla and juxta. 117) P. paulliniae (GTA #2460). 118) N. phocus (GTA #3534). 119) N. broteas (GTA #7211). 120) N. salon salon (GTA #1725).

Figure 121-124. Female genitalia (ventral view) of Pseudonascus and Nascus (from BRAZIL: Rondônia, unless otherwise noted). 121) N. salon salon (GTA #7229). 122) N. broteas (GTA #7228). 123) N. phocus, COSTA RICA (GTA #7230). 124) P. paulliniae (GTA #7233).