Oecetis iara, new species

Figs. 3 A–G

The male of Oecetis iara sp. nov. can be diagnosed by the presence of reticulate patches on abdominal tergites V– VIII, by which it resembles the species of the southwestern Pacific O. reticulata group of Neboiss (1989). However, the new species cannot be placed within the O. reticulata Group because it lacks the distinctive, undivided, dorsal, shield-like tergite VIII, which extends over the genital structures, and also shows dissimilarities in the male genitalic morphology. In O. iara sp. nov. the preanal appendages are oval and flat, while in the species of the O. reticulata Group they are elongate and club-shaped. Additionally, in the new species the inferior appendages are unbranched. Segment IX has the posteroventral margin strongly projected and has one long phallic endothecal spine, both of which are also remarkable characteristics for this species. This is a unique species that does not seem to resemble other species in the Neotropical Region.

Adult male. General color (in alcohol) light brown; legs, palps, and antennae light brown. Forewings with brown spots on membrane at forks, junctions, and at apical ends of veins. Forewings with R2+3 branched at apex of discoidal cell. Hind wings narrowing toward apex, with R2+3 branched near apex of wing; M and Cu1 branched. Length of each forewing: 4.8 mm (n=1) (Fig. 3 A).

Male genitalia. Abdomen with reticulate patches on terga V, VI and VII; tergum VIII with small patches of reticulation. Segment IX short; anterolateral margins rounded in lateral view (Fig. 3 B), posterolateral margins deeply concave, each with small finger-shaped process bearing thick, long seta apically; posterior ventrolateral margins strongly produced caudad and subacute in lateral view (Fig. 3 B); in dorsal view, posterolateral sclerotization of segment IX not reaching dorsal midline, such that dorsal area of segment IX membranous (Fig. 3 C); in ventral view, segment IX slightly produced in blunt angle on midline, posterior ventrolateral margins of segment IX forming long curved processes, each slightly broadened at tip and rounded at apex (Fig. 3 D) Preanal appendages oval, flattened, setose, with rounded apices, shorter than tergum X (Figs. 3 B, 3C). Tergum X divided into 2 portions: dorsal portion single, subtriangular, acute apically as viewed laterally (Fig. 3 B); in dorsal view narrowing apically, apex truncate (Fig. 3 C); ventral portion membranous, divided into two finger-shaped lobes, each tapering to apex, longer than dorsal portion, with 1–2 small setae apically (Fig. 3 B). Inferior appendages unbranched, subrectangular in lateral view, flattened, with external margin smooth; internal margin, as viewed dorsally, with 2 clusters of spine-like setae, one on mesal cleft margin and one on apex; mesal cleft not apparent in ventral view (Figs. 3 B, 3D). Phallic apparatus tubular, curved ventrad, with phallicata membranous. Paramere spine starting from basal third of phallic apparatus, paramere spine strongly sclerotized, curved ventrolaterad with apical third turned to right (Figs. 3 E, 3F).

Holotype male. BRAZIL: Paraná: Foz do Iguaçu, Parque Nacional do Iguaçu, Rio São João, 25°37’13.50”S, 54°28’35.90”W, 178 m, 07.ix.2012, light trap, A.L.H. Oliveira & B. Clarkson leg. (DZRJ 3527).

Distribution. Brazil (Paraná state).

Etymology: The specific epithet iara is a noun in apposition taken from indigenous mythology and Brazilian folklore. According to the folk tale, Iara is a female entity, a beautiful freshwater siren who enchants men with her melodic voice. Iara, from the Tupi language y-îara, means lady or mother of the waters.