Polypedilum (Polypedilum) aymbere, 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 : 521-523

Polypedilum (Polypedilum) aymbere sp. n.

( Figs. 2 A–E)

Type material. Holotype: male, Brazil, São Paulo State, Ubatuba, P 6BJ, madicolous habitat marginal to a small stream, 23˚26’81’’S, 45˚11’57’’W, 1075 m a.s.l., 27.x.2013, E.M. Shimabukuro, G. Perbiche-Neves. ( MZUSP) Paratype: male, Brazil, São Paulo State, Ubatuba, P 6A, madicolous habitat marginal to a small stream, 23˚26’82’’S, 45˚11’58’’W, 1082 m a.s.l., 27.x.2013, E.M. Shimabukuro, G. Perbiche-Neves. ( LEIA)

Etymology. The species name refers to Aymberê, a brave indigenous leader and the greatest symbol of Tamoios’ resistance to Portuguese domination in the region where type-species was found. 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: coloration completely pale; wings hyaline, apex of R 4+5 strongly curved; anal point small and club-shaped; projection of superior volsella proximally enlarged, presenting a lateral seta in the middle of the projection; scale of fore tibia with a long spur.

Descriptions. Male (n=2). Total length 1.62–1.68 mm. Wing length 1.61–1.66 mm. Total length/wing length 1–1.01. Wing length/length of profemur 3.22–3.36.

Coloration: Pale; wings without marking ( Fig. 2A ).

Head. Antenna with 13 flagellomeres. AR 0.39 (1). Ultimate flagellomere 265 µm (1). Frontal tubercle absent. Temporal setae 6–7. Dorsomedial extension 52–60 µm. Clypeus 72 (1) µm long, 58 (1) µm wide, bearing 14 setae. Lengths of palpomeres 1–5 (in µm): 20, 30–32, 51–52, 77–83, 120 (1), respectively. Eyes bare.

Thorax. 4–5 acrostichals, 7–8 dorsocentrals uniserial, 3 prealars, scutellum with 4 setae in a single row.

Wing ( Fig. 2A ). Width 0.28–0.31 mm. VR 1.13–1.18. R with 13–17 setae, R 1 with 5–6, R 4+5 with 20–25 setae. M 1+2 very weak. Brachiolum with a small seta. Squama with 2 setae. Anal lobe poorly developed.

Legs. Scale of fore tibia 30–41 μm long, triangular with a long spur 12–18 μm ( Figs. 2B , 6B ). Spur of middle tibia 44–50 μm long including 16–19 μm long comb. Spur of hind tibia 45–50 μm long including 18–20 μm long comb. Lengths and proportions of legs as in Table 2.

Hypopygium ( Figs. 2C, D ). Tergite IX with two median setae. Anal point 31–34 μm long, broadened in the apex. Gonocoxite 50 μm long. Phallapodeme 45–46 μm long; transverse sternapodeme 31–32 μm long. Superior volsella 31 μm long ( Fig. 2E ), bearing a lateral seta 31–32 μm long. Basal portion of superior volsella with 3 inner setae and few visible microtrichia near them. Inferior volsella 49–57 μm long, bearing a apical seta and 3-4 preapi- cal. Gonostylus 67–78 μm long. HR 0.64–0.75. HV 2.07–2.50.

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 absence of lateral lobes in the anal point.

This new species resembles P. (P.) corniger Sublette et Sasa, 1994 , P. (P.) okueima Bidawid-Kafka, 1996 and P. (P.) paulusi Bidawid-Kafka, 1996 by having the anal point apically club-shaped, wings without marking, and the lateral setae of superior volsella situated in the middle of the projection. However, the new species differs from P. (P.) corniger by the coloration pattern of the body, which is brown to black in P. (P.) corniger and completely pale in P. (P.) aymbere sp. n., and by the apex of R 4+5, which is strongly curved in the new species.

Although P. (P.) okueima also presents a strongly curved ending in R 4+5, it differs from this new species by the shape of the projection of superior volsella, which is completely sharp in P. (P.) okueima and enlarged 2/3 from the base in P. (P.) aymbere sp. n., and by the size of the anal point, which is longer in P. (P.) okueima . The new species also differs from P. (P.) okueima by the long and apically pointed spur on the fore tibial scale (in P. (P.) okueima the fore tibial scale is apically rounded).

This new species differs from P. (P.) paulusi , by the absence of frontal tubercle in the head, the smaller anal point, the notably pronounced spur on the fore tibial scale, and the arrangement of setae on the inferior volsella, which are apically distributed in the new species.

Addtionally, P. (P.) aymbere sp. n. has a lower AR compared to its congeneric ( P. (P.) corniger : 1.08–1.18; P. (P.) okueima : 0.91; P. (P.) paulusi : 0.6), and a lower number of setae on tergite IX ( P. (P.) corniger : 10–11; P. (P.) okueima : 7–9; P. (P.) paulusi : 7).

Figures

FIGURE 2. A–E. Polypedilum (Polypedilum) aymbere 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.