Polypedilum (Tripodura) yvatekaty, Shimabukuro & Trivinho-Strixino & Lamas, 2019

Shimabukuro, Erika Mayumi, Trivinho-Strixino, Susana & Lamas, Carlos José Einicker, 2019, New Polypedilum Kieffer (Diptera: Chironomidae) from mountains of the Atlantic Forest, Brazil, Zootaxa 4612 (4), pp. 518-532 : 523-525

Polypedilum (Tripodura) yvatekaty sp. n.

( Figs. 3 A–E)

Type material. Holotype: male, Brazil, São Paulo State, Campos do Jordão, Campo do Meio Stream , 2 nd order, 22°41’35”S, 45°29’23”W, 1500 m a.s.l., 10.ix.2001, M. T. Suriano. ( MZUSP) Paratype: one male, Brazil, São Paulo State, Campos do Jordão , same data as holotype, except for the date: 07.ii.2001, M. T . Suriano. ( MZUSP) One male, Brazil, São Paulo State, Campos do Jordão, Casquilho Stream , 4 th order, 22°39’49”S, 45°27’04”W, 1535 m a.s.l. 13.ix.2001. ( LEIA)

Etymology. From the indigenous Tupi-Guarani language, Yvatekaty, which means upstream. The name is to be treated as a noun in apposition.

Diagnostic characters. The male of this new species can be separated from other members of the subgenus Tripodura by the combination of the following characters: inconspicuous making on wings, superior volsella distally broadened and rounded with 4–5 inner setae and 2 lateral ones; inferior volsella with a small spot in median region, an apical and 3–4 dorsal setae; conical, crested and broad base of the anal point, with lateral lobes and many lateral setae; gonostylus narrow and elongated.

Descriptions. Male (n=3). Total length 2.44–3.02 mm. Wing length 1.71–2.08 mm. Total length/wing length 1.35–1.59. Wing length/length of profemur 2.44–2.76.

Coloration: Head dark brown; thorax with darker markings in postnotum and preepisternum, scutellum pale; wings with inconspicuous markings (as in Fig. 3A ); legs yellow, all femora brown in proximal and distal part.

Head. Antenna with 13 flagellomeres. AR 0.68–0.92. Ultimate flagellomere 369–400 µm. Frontal tubercle absent. Temporal setae 10–12 (2). Dorsomedial extension 113–116 µm. Clypeus 71–91 µm long, 66–91 µm wide, bearing 14–16 setae. Lengths of palpomeres 1–5 (in µm): 25–31, 44–50, 81–106, 94–125, 175–187, respectively. Eyes bare.

Thorax. 8–15 (2) acrostichals, 10–14 dorsocentrals uniserial, 3–5 prealars, scutellum with 7–9 setae in a single row.

Wing ( Fig. 3A ). Width 0.55–0.66 mm. VR 1.1–1.27. R with 15–20 setae, R 1 with 12–22, R 4+5 with 25–46 setae. Brachiolum with a seta. Squama with 5–8 setae. Anal lobe well developed.

Legs. Scale of fore tibia 45–51 μm long, triangular with apical spur 8–9 μm ( Figs. 3B , 6C ). Spur of middle tibia 53–58 μm long including 22–27 μm long comb. Spur of hind tibia 55–70 μm long including 20–32 μm long spur. Lengths and proportions of legs as in Table 3.

Hypopygium ( Figs. 3C, D ). Tergite IX with 6–9 (2) median setae. Laterosternite with 2 (1) setae. Anal point 52–58 μm long, broad, crested and with 7 (2) setae basally in each side of the anal point and lateral lobes; Gono- coxite 51–66 μm long. Phallapodeme 57–58 μm long; transverse sternapodeme 32–45 μm long. Superior volsella 52–58 μm long, bearing 6–7 setae, including 4–5 inner and 2 lateral ones ( Fig. 3E ). Inferior volsella slender 80–115 μm long with 3–4 dorsal setae and an apical seta; presenting a round and small spot medially. Gonostylus 107–143 μm long. HR 0.36–0.62. HV 2.06–2.28.

Taxonomic discussion. This new species is placed in the subgenus Tripodura due to the combination of wing membrane without macrotrichia, the broad and club-shaped superior volsella completely covered with microtrichia, and the presence of lateral lobes to each side of the anal point.

The male of this new species resembles P. (T.) aparai Bidawid et Fittkau, 1995 due to the format of superior volsella, distally swollen and rounded and the number of setae on it. Additionally, both species have femora with dark marking. However, both species are distinguishable by the marking patterns on wings. The markings on wings of P. yvatekaty sp. n. are inconspicuous and restricted to a few cells, while in P. (T.) aparai markings are noticeably darker, wider and spread all over the wing. Both species also differ by the number of setae on inferior volsella (three dorsal setae in the new species and two dorsal setae in P. (T.) aparai), and the shape of gonostylus, which is narrower and elongated in the new species.

Figures

FIGURE 3. A–E. Polypedilum (Tripodura) yvatekaty sp. n. male adult. A, wing. B, scale of fore tibia. C. hypopigyum, dorsal view. D, hypopigyum with tergite IX removed, dorsal view. E, superior volsella.

FIGURE 6. A–E. Scale of fore tibia. A, Polypedilum (Polypedilum) caete. B, Polypedilum (Polypedilum) aymbere. C, Polypedilum (Tripodura) yvatekaty. D, Polypedilum (Tripodura) goiocoio. E, Polypedilum (Tripodura) ybytyra. F. Thorax of P. (T.) ybytyra with the detail of the scutal tubercle.