Sesommata leuroptera

Sesommata leuroptera

ADULT (Figures 397, 398).—Length of forewing: , 5–7 mm; , 6.5–7 mm. A moderately small moth with smooth, brownish fuscous to black forewings in the male, rarely with a few scattered white scales; forewings of female usually light in color, with white scales along costa and scattered over distal half.

Head: Vestiture fuscous to gray in male; pale buff in female. Antennae approximately 0.6–0.7 the length of forewing, 42–segmented; scape black to brownish fuscous dorsally, dull white to cream ventrally; pecten consisting of 6–8 dark hairs; flagellum black to brownish fuscous dorsally, white to pale buff ventrally. Maxillary palpi white to cream. Labial palpi mostly white; apical segment fuscous over lateral-ventral surfaces; second segment with 6–8 dark hairs mostly concentrated at distal end.

Thorax: Pronotum black in male, more brown in female. Venter white to cream. Forewings black to brownish fuscous in male, rarely with scattered white scales over distal third; vestiture entirely smooth, without rough scaling over base of Cu; ventral surface without specialized sex scales; forewings of female generally lighter, more brown in color, with white along costal margin or scattered over distal half; fringe black to brown, often irrorated with white in female. Hind wings as dark as forewings, pale gray to white along basal two-thirds of costal margin; costal hair pencil absent. Forelegs dark fuscous to brown dorsally, pale gray to white ventrally; tarsi banded with pale buff. Midlegs and hind legs generally paler in color, with tarsal banding and ventral surfaces more white.

Abdomen: Black to brownish fuscous dorsally; pale buff to white ventrally. Male without lateral sex scales.

Male Genitalia: As shown in Figures 439–442. Uncus bilobed; lobes broadly conical, widely separated. Gnathos a relatively large, median lobe bearing a single large spine. Valvae slender, terminating in a complex, irregularly trilobed apex. Anellus highly asymmetrical, with a broad prominent lobe bearing a dense cluster of apical spines arising on left side. Aedoeagus with apex relatively narrow and somewhat twisted in a spiral, a prominent lobe bearing numerous large spines arising from left side.

Female Genitalia: As shown in Figure 557. Apex of ovipositor broad, approximately 0.8 mm wide. Colliculum with thickened, folded, densely spiculated walls. Corpus bursae covered internally with evenly distributed minute spicules; signum absent. Spermatheca extremely long, approximately twice the length of bursa copulatrix; utriculus elongate, slender, and without spicules; a slender lateral lagena arising near posterior end.

IMMATURE STAGES.—Unknown.

HOLOTYPE.—. Rincon de la Piedra, 20 km S Valdivia, 180 m, Valdivia Province, Chile, 15 Nov 1981, Nielsen and Karsholt (ZMUC).

PARATYPES.—ARGENTINA. Neuquen Prov.: Junin de los Andes, 1000 m, Laguna Verde: 1, 11 Mar 1979, E.S. Nielsen. Lago Lacar, Pucará, 750 m, 1, 26 Dec 1978, E.S. Nielsen. Tierra del Fuego Prov.: Ushuaia, Lapatafa, 20 m, 5, 30 Jan 1979, E.S. Nielsen.

CHILE. Osorno Prov.: Parque Nacional Puyehue, Antillanca, 1100–1300 m, 2, 11 Dec 1981, Nielsen & Karsholt. Valdivia Prov.: Valdivia, 20 m, 1, 15 Nov 1981, Nielsen & Karsholt. Rincon de la Piedra, 180 m, 20 km S Valdivia, 4, 3, 14 Nov 1981; 18, 5, 15 Nov 1981, Nielsen & Karsholt.

Paratypes in ANIC, BMNH, MACN, MHNS, USNM, and ZMUC.

HOST.—Unknown.

FLIGHT PERIOD.—14 November to 11 March; univoltine?

DISTRIBUTION (Map 3).—The range of this species appears to be centered in the more southern temperate forests of Argentina and Chile, suggesting a biology that is more cool adapted than most Palaephatidae. In Argentina it has been collected in the montane forests of Neuquen Province and as far south as the extreme tip of Tierra del Fuego. It has been encountered from only two rather diverse sites in Chile, from the higher elevations of Puyehue National Park and at a low coastal elevation near Valdivia.

ETYMOLOGY.—The specific epithet is derived from the Greek leuros (smooth, level) plus pteron (feather, wing) and refers to the smooth scale vestiture over the entire forewing of the male.