Tanytarsus pinedoi, Dantas & Hamada & Giłka, 2023

Dantas, Galileu P. S., Hamada, Neusa & Giłka, Wojciech, 2023, Tanytarsus van der Wulp (Chironomidae, Diptera): new species from the western Amazon region in Peru and Brazil, new records from the Neotropics, and remarks on the taxonomy of the genus, Zootaxa 5271 (1), pp. 115-139 : 125-127

Tanytarsus pinedoi sp. nov.

https://zoobank.org/ urn:lsid:zoobank.org:act:F8231DFE-C627-4F3B-A9C6-290402B524EB

( Fig. 5A–F )

Type material. Holotype ♁, PERU, Cusco, Quincemil, Araza river tributary, 13º20′10′′S, 70º50′57′′W, 874 m a.s.l., 23–31.viii.2012, Malaise trap, J.A. Rafael, R. R. Cavichioli, D.M. Takiya ( MUSM) . Paratype: 1 ♁ ( INPA), same data as holotype .

Derivatio nominis. The species is named in honour of the young Peruvian researcher Raul Bismarck Pinedo Garcia, for his friendship and constant support both in the laboratory and field works.

Diagnosis. Tergite IX covered with dense short microtrichia on the entire surface, median setae absent, tergite bands short, broadly separated.Anal point slender, pointed, without crests, bars or spinulae. Superior volsella basally rounded, tapering to truncate and posteriorly or posterolaterally curved apex bearing ventral lip; digitus triangular, basally broad but strongly shortened. Median volsella with two setiform and one foliate lamella.

Description. Adult male (n = 2)

Body size and proportions. Total length 2.03–2.15 mm. Wing length 1.05 mm. Total length/wing length 2.04. Wing length/length of profemur 2.22.

Colouration. Head capsule and palps light brown, eyes black, antenna brown. Scutal vittae, postnotum and preepisternum brown, ground colour of thorax, haltere, scutellum, yellow to light brown. Legs light brown. Wing veins yellow to light brown, membrane with light brownish undertone. Abdomen yellowish.

Head. Eyes bare, with well-developed dorsomedian extensions. Antenna with 13 flagellomeres; ultimate flagellomere 140–163 μm long; AR 0.33–0.37. Frontal tubercles 6–7 μm long. Tentorium 70–78 μm long. Temporal setae 7–8 on each side. Clypeus with 8–10 setae. Lengths of palpomeres 1–5 (in μm): 22–25, 23–26, 76–78, 78–80, 130–135; third palpomere with 2 sensilla clavata subapically, 12 μm long.

Thorax. Ac about 20, restricted to anterior region of scutum; Dc 7–8 on each side, uniserial; Pa 1 on each side; Scts 5. Scutum projected and rounded anteriorly, overreaching antepronotum.

Wing. Obovate, with anal lobe reduced. Almost all veins (except subcosta) and entire membrane posterior to radial veins area (except 1/2 basal of m and cu cells) covered with macrotrichia. Brachiolum with 1 seta. VRCu 1.36.

Legs. Foreleg tibia with lanceolate spur 18–20 μm long. Tibial combs of mid and hind legs separated; spurs of mid leg unequal: one apically curved, 17–18 μm long, second straight, 10–12 μm long; spurs of hind leg unequal: one apically curved, 18–20 μm long, second straight, 10–12 μm long. Basitarsus of mid leg without sensilla chaetica. Lengths and proportions of legs as in Table 4.

Hypopygium. Tergite IX covered with dense short microtrichia on the entire surface, median setae absent, 4–5 setae on each side of anal point; lateral teeth vestigial; tergite bands short, broadly separated (not reaching middle of tergite) ( Fig. 5A ). Anal point hyaline, slender, pointed, without crests, bars or spinulae ( Fig. 5A, C ). Superior volsella 24–25 μm long, basally rounded, tapering to truncate and posteriorly or posterolaterally curved apex bearing distinct ventral lip; 3–4 setae dorsally, 2 setae on median margin and 1 seta on anteroventral tubercle, microtrichia on dorsal surface absent; digitus triangular, basally broad but strongly shortened (4–5 μm), not reaching margin of superior volsella ( Fig. 5A–E ). Stem of median volsella simple, 14–18 μm long, with two setiform and one foliate lamella ( Fig. 5E, F ). Inferior volsella 45–50 μm long, with slightly swollen and posteromedially directed distal part ( Fig. 5A, B ). Phallapodeme sinuous, 55–65 μm long; transverse sternapodeme 36–45 μm long, with small oral projections. Gonocoxite 60–70 μm long. Gonostylus 46–50 μm long, slightly swollen at mid length, evenly tapering toward blunt apex. HR 1.30–1.40, HV 4.06–4.67.

Female and immature stages. Unknown.

Taxonomy. The male of Tanytarsus pinedoi is characterized by a unique hypopygium structure, the comparison of which with those of other known Tanytarsus is limited to species with a slender anal point without crests and/or spinulae, or other structures typical of the genus ( Fig. 5 ). Among the Neotropical Tanytarsus , a similar anal point is known in T. fastigatus Reiss, 1972 (but broader in distal half), T. hirsutus Trivinho-Strixino, Wiedenbrug et da Silva, 2015 (parallel-sided), T. jatai Trivinho-Strixino, Wiedenbrug et da Silva, 2015 (with minute subapical triangular protrusions), T. obiriciae Trivinho-Strixino et Sonoda, 2006 (broadened in distal half), T. reissi Paggi, 1992 (triangular at tip), T. sanseverinoi Dantas, Amat, Hamada et Giłka, 2022 (nearly identical with T. pinedoi ), T. tuberculatus Reiss, 1972 (with vestigial crests or flap-like enlargements), and in species of the impar group (but shorter, broader or with narrow crest) ( Reiss 1972, Paggi 1992, Trivinho-Strixino & Strixino 2004, Trivinho-Strixino & Sonoda 2006, Trivinho-Strixino et al. 2015, Dantas & Giłka 2017, Dantas et al. 2022). The simple (bare) and slender anal point, but with round apex, we also describe in other new species here (see T. kaxinawa ). None of the species compared here has characters in a combination given in the diagnosis of T. pinedoi (see above). Apart from the unique anal point structure, the species is distinct in having the superior volsella with its posteriomedian part truncate, curved posteriorly or posterolaterally, and the digitus, basally broad but short.

Geographical distribution and bionomics. Tanytarsus pinedoi is known only from the type locality in the highlands of the Amazonian Forest in Peru ( Fig. 1A, B ). The adult male specimens examined were obtained along with those of four other species described in the present paper. For further information on the ecology and bionomics refer to the notes on Tanytarsus aries (above).

Figures

FIGURE 1. Sites of sampling the type material in Peru (A, B) and Brazil (C, D).

FIGURE 5. Tanytarsus pinedoi sp. nov., male. A, B: hypopygium in dorsal (A) and ventral aspect (B); C: anal point and superior volsellae in dorsal aspect; D: superior volsella and digitus (variations); E: median and superior volsellae in ventral aspect; F: median volsella; C–F magnified × 2–3 relative to A and B; superior volsella in the drawings (red) with anteroventral tubercle (yellow), and digitus (green).