Pseudopostega bidorsalis Davis & Stonis 2007

Pseudopostega bidorsalis

ADULT. Figure 219. Length of forewing 2.5–3.0 mm. Small, mostly white moth with white forewings marked by a large, dark brown dorsal spot extending most of the length of hind margin, a pair of brown, subapical costal strigulae, a pair of faint, short, brown, tornal strigula, and a small, elongate, dark brown apical spot. Male gnathos with broad, short, slightly arched basal fold and deeply divided caudal lobe (Figure 385). Papillae anales of female minutely bilobed, with nearly sessile to moderately stalked base; lobes short (Figures 485, 486).

Head: Vestiture white. Scape white; flagellum light golden brown, 53–56-segmented. Palpi white; labial palpus with suffusion of brown dorsally.

Thorax: White; tegula with light brown suffusion on anterior margin. Forewing white marked by a large, dark brown dorsal spot extending most the length of hind margin, 2–3 dark brown, subapical costal strigulae, a pair of faint, short, dark brown, tornal strigulae, and a small, elongate, dark brown apical spot; strigula 1 faint, short, absent in most specimens examined; strigula 2 merging apically with elongate dark brown apical spot and then continuing a short distance caudally as a tornal strigula; strigula 3 curving distad around apical spot; terminal and dorsal cilia white to brown; venter of forewing light brown, with basal, subhumeral white area. Hindwing and cilia brown dorsally and ventrally. Legs mostly white; foreleg with dorsal surfaces partially suffused with light brown; tarsomeres of all legs partially suffused with light brown dorsally.

Abdomen: Light golden brown dorsally, white ventrally.

Male Genitalia: Figures 385, 386. Socii a pair of relatively small, rounded, setose lobes, widely separated by a distance ~0.5× length of cucullar lobe; caudal rim of uncus deeply concave. Vinculum broadly rounded; anterior margin slightly truncate. Base of gnathos broadly triangular; basal fold narrow, anterior margin slightly concave; gnathos abruptly narrows caudally to a deeply furcate caudal lobe; lobe divided nearly to base. Valva with an elongate cucullar lobe ~0.45× length of genital capsule, bearing a pectinifer consisting of ~37 blunt spines; distal apex of cucullar lobe slightly extended as a short, setose lobe; pedicel moderately broad, ~0.13× length of cucullar lobe; valva moderately long, length along sacculus ~0.75× length of genital capsule; saccular lobe elongate, tapering to narrow, rounded, setose apex; basal process of valva tapering to acute apex, approximately equal to length of costal lobe. Juxta a slender, elongate, median rod.

Female Genitalia: Figures 484–486. Abdomen tapering to slender, cleft apex. Each posterior apophysis divided nearly half its length before fusion; fused portion relatively short. Papillae anales minutely bilobed, with nearly sessile to moderately stalked base; lobes short, bearing ~6–7 elongate setae. Vestibulum moderately narrow, membranous. Ductus bursae gradually enlarging anteriorly, densely lined with pectinations comprised usually of 2–4 spicules arranged in short, transverse rows; pectinations gradually terminating along one side of caudal end of corpus bursae. Corpus bursae elongate, elliptical, gradually narrowing to ductus; a narrow, faint, elliptical band of tubercular outgrowths extending most the length of corpus. Ductus spermathecae elongate, ~0.6× length of bursa copulatrix; membranous outer canal short, slender; inner canal sinuate, terminating in 4–5 convolutions; vesicle composed of an abruptly enlarged, tightly coiled lobe.

LARVA AND PUPA. Unknown.

HOLOTYPE. ♂; COSTA RICA: HEREDIA: Estación Biológica La Selva, L/17/474, 50–150 m: 24 Sep 1998, INBio-OET, slide DRD 4337 (INBIO).

PARATYPES. COSTA RICA: CARTAGO: Turrialba, 600 m: 1 ♀, Jun 1972, V. O. Becker, 36930 (VOB). HEREDIA: Estación Biológica La Selva, 50–150 m, L/17/474: 1 ♀, 24 Sep 1998, INBio-OET, slide USNM 33098 (USNM); L/12/481: 1 ♀, 6 Oct 1998, INBio-OET, slide: DRD 4332 (INBIO); Lab area, L006: 1 ♀, 10–17 Jan 1993, INBio-OET, slide DRD 4338 (INBIO). GUANACASTE: Estación Cacao, Lado SO Volcán Cacao, P. N. Guanacaste, 1000–1400 m: 1 ♀, Aug 1990; 1 ♂, 1 ♀, 23 Oct–9 Nov 1990, C. Chaves, slides DRD 4339, USNM 32447, 33096, (INBIO, USNM).

HOST. Unknown.

FLIGHT PERIOD. Adults have been collected from August to October and January.

DISTRIBUTION. (Map 15) Known only from northern Costa Rica.

ETYMOLOGY. The species name refers to two major morphological characters of this moth, which are derived from the Latin bi (two, double) in reference to the bifurcate apex of the male gnathos, and dorsualis (dorsalis) (of the back) in reference to the prominent forewing dorsal spot.

DISCUSSION. The forewing pattern of P. bidorsalis superficially resembles that of P. colognatha and latifurcata latifurcata from the West Indies and the Costa Rican P. dorsalis dorsalis. All species are easily distinguished on the basis of male genital characters, with the gnathi of colognatha and dorsalis possessing a simple, acute caudal lobe and that of latifurcata being more narrow with a dorsally reflexed caudal lobe. The deeply furcate male gnathos of bidorsalis most resembles that of a few other members of the divaricata group, particularly P. quadristrigella from North America, but the forewings of the latter lack the enlarged dorsal spot of bidorsalis. The female papillae anales within bidorsalis vary noticeably in width but are consistently minutely bilobed.

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

The length of the forewings is 2.5–3 mm. Adults have been recorded from August to October and January.