Polypedilum (Polypedilum) caete, 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 : 519-521

Polypedilum (Polypedilum) caete sp. n.

( Figures 1 A–F)

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., 11.ii.2002, M. T. Suriano. ( MZUSP) . Paratype: male, Brazil, São Paulo State, Campos do Jordão, Galharada Stream , 1 st order, 22°41’33”S, 45°27’55”W, 1554 m a.s.l., 14.ii.2002, M. T . Suriano. ( LEIA)

Etymology. From the indigenous Tupi-Guarani language, Caetê, meaning the original forest. 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 Polypedilum s. str. by the combination of the following characters: well developed and curved projection of superior volsella and presence of a long lateral seta on it; presence of 4–6 setae arranged in a row on inferior volsella; presence of weak marking on wings and RM distinctly darkened; scale of fore tibia apically truncated.

Descriptions. Male (n=2). Total length 2.55–2.89 mm. Wing length 1.42–1.65 mm. Total length/wing length 1.75–1.8. Wing length/length of profemur 1.85–2.15.

Coloration: Head brown; thorax brown, preepisternum and anepisternum dark brown; wings with weak markings, RM distinctly dark brown, M 1+2 weak ( Fig. 1A ); legs light brown; base of profemur darker.

Head. Antenna with 13 flagellomeres. AR 0.67–0.77. Ultimate flagellomere 312–325 µm. Frontal tubercle absent. Temporal setae 9–10. Dorsomedial extension 85–90 µm. Clypeus 78–89 µm long, 51–52 µm wide, bearing 15–19 setae. Lengths of palpomeres 1–5 (in µm): 25, 31–37, 75–87, 81–103, 125 (1), respectively. Eyes bare.

Thorax. 10 acrostichals, 18 dorsocentrals uniserial, 3 prealars, scutellum with 6 setae in a single row.

Wing ( Fig. 1A ). Width 0.52–0.54 mm. VR 0.86–1.1. R with 22–26 setae, R 1 with 11–12, R 4+5 with 21–25 setae. Brachiolum with a seta. Squama with 4–5 setae. Anal lobe poorly developed.

Legs. Scale of fore tibia 28–31 μm long, truncated, without spur ( Figs. 1B , 6A ). Spur of middle tibia 56–60 μm long including 21–27 μm long comb. Spur of hind tibia 59–60 μm long including 21–22 μm long comb. Lengths and proportions of legs as in Table 1.

Hypopygium ( Figs. 1C, D ). Tergite IX with 9–10 median setae. Anal point 58–60 μm long, narrow and elon- gated. Gonocoxite 58–69 μm long. Phallapodeme 43–54 μm long; transverse sternapodeme 52–61 μm long. Su- perior volsella 54–61 μm long ( Fig. 1E ), bearing a lateral seta 65–75 μm. Basal portion of superior volsella with microtrichia and 3–4 inner setae. Inferior volsella slender 92–101 μm long, with 4–6 setae arranged in a row ( Fig. 1F ). Gonostylus 135–137 μm long. HR 0.42–0.51. HV 1.86–2.14.

Taxonomic discussion. This new species is placed in Polypedilum s. str. based on the combination of wing membrane without macrotrichia, superior volsella with a projection, and the absence of lateral lobes in the anal point. Although this new species do not present frontal tubercles and present a long lateral seta in the projection of superior volsella, as most members of Polypedilum s. str., these characters are not consistent to define Polypedilum s. str. species ( Cranston et al. 2016; Yamamoto & Yamamoto 2016).

This new species resembles P. (P.) solimoes Bidawid-Kafka, 1996 , due to the narrow and parallel-side anal point and the position of lateral setae on superior volsella. However, it differs by the number and arrangement of setae on inferior volsella (in P. (P.) solimoes the setae are irregularly distributed while in the new species they are aligned), the presence of weak marking on wings, and the truncate end of the fore tibial scale (which is apically pointed in P. (P.) solimoes ).

This new species also resembles P. (P.) marauia Bidawid-Kafka, 1996 , due to the presence of weak markings on wings, as well as the format of the anal point and the position of lateral setae on superior volsella. It differs by the longer lateral seta on superior volsella, the format of inferior volsella (distally tapering in the new species and round in P. (P.) marauia ).

Additionally, this new species differs from all congeneric by the pronounced color on RM vein.

Figures

FIGURE 1. A–F. Polypedilum (Polypedilum) caete 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. F, inferior 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.