Pseudopostega divaricata Davis & Stonis 2007

Pseudopostega divaricata

ADULT. Figure 220. Length of forewing 3.5–4.8 mm. Small, mostly white moth with white forewings variably marked with a usually large, relatively suffused, faint to light brown spot sometimes obliquely oriented across middle of wing, 2 light to dark brown, subapical costal strigulae, a similarly suffused, light brown area basal to first strigula, and a small, dark brown to fuscous apical spot. Male gnathos triangular, gradually tapering to a strongly divergent, furcate, caudal lobe (Figure 387). Papillae anales of female bilobed; lobes short, broadly round, densely setose (Figure 488).

Head: Vestiture white. Scape white; flagellum light golden brown, 62–70-segmented. Palpi cream; labial palpus with suffusion of dark brown dorsally.

Thorax: White; tegula with suffusion of dark brown on anterior margin. Forewing white, variably marked with a usually large, relatively suffused, faint to light brown spot, typically obliquely oriented across middle of wing, occasionally absent; 2 light to dark brown, subapical costal strigulae present; strigula 1 brown, fading caudally into large, suffused, light brown spot near middle of wing apex before dark brown to fuscous apical spot, sometimes continuing caudally as a short, faint, brown, tornal strigula; strigula 2 usually curving around apical spot to tornus; terminal and dorsal cilia mostly white, sometimes with brownish suffusion along basal and apical margins of strigula 2; cilia along basal half of dorsal margin brown; venter of forewing brown with basal, subhumeral white area. Hindwing and cilia brown dorsally and ventrally. Legs mostly cream; foreleg with dorsal surfaces heavily suffused with dark brown; tarsi of mid- and hindlegs often banded with brown dorsally, especially on terminal segments.

Abdomen: Brown dorsally, white to cream ventrally.

Male Genitalia: Figures 387, 388. Socii a pair of relatively long, rounded to subacute, setose lobes widely separated by a distance ~0.66× length of cucullar lobe; caudal rim of uncus shallowly to moderately deeply concave. Vinculum broad, tapering to narrowly truncate to slightly concave anterior margin. Base of gnathos broad, abruptly narrowing posteriorly to moderately stout, caudal lobe with widely divergent, moderately recurved, furcate arms; anterior margin of gnathos slightly concave, with broad, short, slightly arched basal fold (Figure 387). Valva with an elongate cucullar lobe ~0.45× length of genital capsule, bearing a pectinifer consisting of ~41–48 relatively elongate, slender, blunt spines; terminal apex of cucullar lobe extended slightly as a narrowly rounded, setose lobe; pedicel moderately elongate, stout, approximately 0.25–0.3× length of cucullar lobe; valva elongate, length along sacculus ~0.65× length of genital capsule; saccular lobe moderately slender, tapering to rounded apex; basal process of valva tapering to acute apex that extends to inner anterior margin of vinculum, exceeding length of costal lobe. Juxta a slender projection from vinculum.

Female Genitalia: Figures 487, 488. Apex of abdomen densely setose, appearing rounded but minutely cleft. Each posterior apophysis fused most its length, short, relatively stout, length ~1.5× maximum width of papillae anales, slender. Papillae anales bilobed; lobes short, length ~ equal to width, broadly rounded, densely setose, arising from narrow, triangular base. Vestibulum broad, membranous. Ductus bursae with pectinations consisting of transverse rows of usually 2–6 blunt, minute spicules; pectinations continue as dense field well into ductus bursae. Corpus bursae moderately large, elongate, length ~ equal to length of ductus spermathecae; a faint, oval band of relatively large, irregularly shaped, external tubercles extending most the length of bursa. Ductus spermathecae nearly as long as corpus bursae, emerging from ductus spermathecae via an enlarged, membranous, saccular outer canal; elongate inner canal terminating in approximately 4 small convolutions; vesicle a relatively complex, divided tube, with longer branch tightly coiled.

LARVA AND PUPA. Unknown.

HOLOTYPE. ♂; ARGENTINA: JUJUY: 3 km NE Caimancito, 23 km ENE Calilegua, sta. 18, 500 m: 26 Nov 1995, Neth. Ent. Exp. N.Arg., slides DRD 4136 (RMNH).

PARATYPES. ARGENTINA: JUJUY: 3 km NE Caimancito, 23 km ENE Calilegua, sta. 18, 500 m: 4 ♂, 1 ♀, 26 Nov 1995, Neth. Ent. Exp. N. Arg., slides DRD 4137, USNM 32457, 32458 (RMNH USNM). SALTA: 2 km NW Campo Quijano, 31 km WSW Salta, sta. 58, 1600 m: 1 ♀, 30 Jan 1996, Neth. Ent. Exp. N. Arg., slide DRD 4153 (RMNH).

HOST. Unknown.

FLIGHT PERIOD. Adults have been collected in January and November.

DISTRIBUTION. (Map 15) Known only from northern Argentina.

ETYMOLOGY. The species name is derived from the Latin divaricatus (spread apart) in reference to the greatly divergent, furcate apex of the male gnathos.

DISCUSSION. The male of P. divaricata is distinguished from all other Pseudopostega by the widely divergent, moderately recurved, caudal lobes and broad, smoothly triangular base of the gnathos.

The latifurcata group

The male gnathos within the members of the latifurcata group is morphologically similar in being relatively narrow with a bifurcate caudal lobe, without a basal fold, and with a pair of slender, lateral folds. The valva possesses a prominent saccular lobe, and the length of the entire sacculus ranges from approximately 0.5× to nearly 0.8× the length of the genital capsule. The vinculum is broad, with a subtruncate to slightly sinuate anterior margin. Usually some vestige of a rod-like juxta is evident.

Pseudopostega divaricata is a moth of the family Opostegidae. It was described by Donald R. Davis and Jonas R. Stonis, 2007. It is known from northern Argentina.

The length of the forewings is 3.5–4.8 mm. Adults have been recorded in January and November.