Sesommata paraplatysaris

Sesommata paraplatysaris

Adult (Figures 403, 404).—Length of forewing: , 5–6.2 mm; , 5–6.5 mm. A small species possessing dark fuscous forewings in the male, lightly irrorated with white apically, and with a rounded mass of broad sex scales over bases of Cu and A; forewings of female more brown, irrorated with white scales; costal margin usually with two cream spots beyond middle.

Head: Vestiture black in male to light brown or dull white in female; lower frons with grayish buff to white piliform scales. Antennae approximately 0.5–0.6 the length of forewing, 38–43- segmented; scape black to brown dorsally, white ventrally; pecten consisting of 6–12 dark hairs; flagellum fuscous to brown dorsally, thinly covered with buff to white scales ventrally. Maxillary palpi buff to white. Labial palpi mostly cream to white; apical segment with lateral-ventral surfaces fuscous; second segment with 8–12 brownish hairs laterally.



Thorax: Pronotum black to dark brown; rarely heavily suffused with cream white. Venter white. Forewings dark fuscous in male, slightly irrorated with white toward apex; a relatively large, rounded mass of broad sex scales present near base of Cu and A; outer dark scales often missing and exposing underlying broad, white sex scales beneath; ventral side of forewing with two elongate patches of cream sex scales parallel to Cu; female more brown, irrorated with white over distal half; two cream-white elongate spots usually present along costal margin, one at middle and another at subapex; fringe fuscous, irrorated or streaked with white. Hind wings dark fuscous with basal two-thirds to one-half of costal area white in both sexes; male with a long white hair pencil from base to almost half way along costal margin. Forelegs fuscous dorsally, white ventrally; tarsi indistinctly banded with white. Midlegs somewhat paler, more gray dorsally, white ventrally; tarsi more distinctly banded. Hind legs similar to midlegs in color; male with elongate, white to buff hair pencils arising from dorsum of tibiae.

Abdomen: Dark fuscous dorsally, cream to white midventrally, with grayish suffusion near sides. Pleuron of A2–3 in male with dense cluster of short, rounded, pale-orange to cream sex scales.

Male Genitalia: As shown in Figures 447–450. Uncus bilobed; lobes as broad or broader than relatively narrow separation. Gnathos a relatively large, elongate triangular plate bearing a dense cluster of short, stout spines at caudal apex. Vinculum-saccus relatively narrow, only slightly broader than long; length greater than that of S. platysaris, approximately 0.8–1 that of valva; anterior apex of saccus evenly rounded. Valvae broad at base, tapering rather abruptly to a slender, attenuated apex; an elongate digitate process arising subapically and directed mesally; length of process 0.9–1.0 the maximum width of valva. Anellus with lateral arm elongate, slender, slightly curved to a simple, smooth apex; length exceeding that of S. platysaris, approximately 1.5 the length of aedoeagus. Aedoeagus with caudal fifth abruptly bent ventrally 90°; dorsum of refexed portion densely covered with numerous short spines; apex subacute; aedoeagus without a ventral, subapical perforation for vesica.

Female Genitalia: As shown in Figure 561. Apex of ovipositor relatively narrow, approximately 0.4 mm wide. Colliculum with heavily thickened, folded walls bearing a dense concentration of mostly broad spicules. A rather distinct, approximately triangular, sclerotized plate present in dorsal wall of vaginal passage immediately caudad of colliculum. Corpus bursae with numerous, evenly dispersed spicules on inner wall; a single, spinose signum, arising from an irregularly circular base, present near anterior end of corpus. Spermatheca relatively short, only slightly exceeding length of bursa copulatrix; utriculus relatively small and slender, without spiculated walls; lateral lagena absent.

IMMATURE STAGES.—Unknown.

HOLOTYPE.—, Pucará, 650 m, Lago Lacar, Neuquen Province, Argentina, 28–29 Nov 1981, Nielsen & Karsholt, DRD genitalia slide 3505 (ZMUC).

PARATYPES.—ARGENTINA. Neuquen Prov.: Lago Lacar, Pucará, 3, 25 Nov 1978, E.S. Nielsen; same locality, 650 m, 3, 2, 28–29 Nov 1981, Nielsen & Karsholt; same locality, 750 m, 1, 1 Dec 1978; 1, 2 Dec 1978; 4, 1, 3 Dec 1978; 1, 26 Dec 1978, E.S. Nielsen. Lago Lacar, 5 km E of Hua-Hum, 640 m, 3, 25 Nov 1981, Nielsen & Karsholt. Paso Puyehue, 1300 m, 2, 10 Dec 1981, Nielsen & Karsholt. San Martin de los Andes, Cerro Chapelco, 1400–1600 m, 1, 27 Nov 1981; 1, 20–25 Dec 1981, Nielsen & Karsholt. Rio Negro Prov.: San Carlos de Bariloche, Colonia Suiza, 800 m, 1, 4 Dec 1981, Nielsen & Karsholt; same locality, 810 m, 5, 9 Dec 1978, E.S. Nielsen. San Carlos de Bariloche, Pampa del Toro, 900 m, 1, 9–10 Nov 1981, Nielsen & Karsholt; same locality, 1000 m, 1, 21 Nov 1978, E.S. Nielsen.

CHILE. Malleco Prov.: Near Los Gringos Camp, 1300 m, Nahuelbuta National Park, 1, 1, 6–11 Jan 1982, D.R. Davis, sweeping. Ñuble Prov.: Alto Tregualemu, 500 m, ∼20 km SE of Chovellen, 2, 1–3 Dec 1981, D.R. Davis, sweeping. Osorno Prov.: 20 km. W of Entre Lagos, 100 m, 1, 17 Nov 1981, Nielsen & Karsholt.

Material deposited in ANIC, BMNH, MACN, USNM, and ZMUC.

HOST.—Unknown.

FLIGHT PERIOD.—9 November to 11 January; univoltine.

DISTRIBUTION (Map 4).—This species is restricted to the mostly montane, temperate forests of southern Argentina and Chile. In Argentina it has been collected near Lago Lacar and Lago Nahuel Huapi in western Neuquen and Rio Negro provinces. In Chile it is known to occur in the coastal ranges from Ñuble Province south to Malleco Province and along the Andes near Puyehue National Park.

ETYMOLOGY.—The specific epithet is derived from the Greek para (near, close) as a prefix to the name of the following species, S. platysaris, to indicate the close affinities of these two species.